diff --git a/.eslintrc.js b/.eslintrc.js
index 33969eb..eab1588 100644
--- a/.eslintrc.js
+++ b/.eslintrc.js
@@ -8,7 +8,14 @@ module.exports = {
     '@ridi/eslint-config/typescript',
     '@ridi/eslint-config/prettier',
   ],
-  overrides: [],
+  overrides: [
+    {
+      files: ['src/**/models/*.ts'],
+      rules: {
+        camelcase: 0,
+      },
+    },
+  ],
   rules: {
     'no-console': 0,
     semi: [2, 'always'],
@@ -18,7 +25,8 @@ module.exports = {
     'import/no-unresolved': 0,
     'import/extensions': 0,
     'no-void': 1,
-    'no-shadow': 1,
+    'no-shadow': 0,
+    '@typescript-eslint/no-shadow': 0,
     '@typescript-eslint/ban-ts-comment': 1,
     '@typescript-eslint/no-unsafe-assignment': 1,
     '@typescript-eslint/no-unsafe-call': 1,
@@ -32,6 +40,8 @@ module.exports = {
     'import/prefer-default-export': 0,
     'func-names': 0,
     '@typescript-eslint/no-empty-function': 1,
+    'max-classes-per-file': ['error', 10],
+    'lines-around-comment': 0,
   },
-  ignorePatterns: ['**/node_modules/**'],
+  ignorePatterns: ['**/node_modules/**', '**/dist/**'],
 };
diff --git a/package-lock.json b/package-lock.json
index a6dd1cf..48033ba 100644
--- a/package-lock.json
+++ b/package-lock.json
@@ -1,6 +1,6 @@
 {
   "name": "@ridi/event-tracker",
-  "version": "0.10.2",
+  "version": "0.11.0-alpha.7",
   "lockfileVersion": 1,
   "requires": true,
   "dependencies": {
@@ -466,6 +466,12 @@
       "resolved": "https://registry.npmjs.org/@types/google.analytics/-/google.analytics-0.0.39.tgz",
       "integrity": "sha512-AwVtVYACQg26MJz+752H6uskn53BR7eilCOHksUGkzobZNKc7O3RFTJrbD3yKAluXy6favVdynnr9btijjcakQ=="
     },
+    "@types/gtag.js": {
+      "version": "0.0.3",
+      "resolved": "https://registry.npmjs.org/@types/gtag.js/-/gtag.js-0.0.3.tgz",
+      "integrity": "sha512-iRF/4Q3G1t0OTNMjK52tpGSQPgEsYzWQL1IdVXt9BywK6MUK3ypB7LaoEQa8sW9gPXENoU1xAyCxqJhMkB2rCA==",
+      "dev": true
+    },
     "@types/istanbul-lib-coverage": {
       "version": "2.0.1",
       "resolved": "https://registry.npmjs.org/@types/istanbul-lib-coverage/-/istanbul-lib-coverage-2.0.1.tgz",
diff --git a/package.json b/package.json
index 5afe414..096191b 100644
--- a/package.json
+++ b/package.json
@@ -1,6 +1,6 @@
 {
   "name": "@ridi/event-tracker",
-  "version": "0.10.2",
+  "version": "0.11.0-alpha.7",
   "description": "",
   "main": "dist/cjs/index.js",
   "typings": "dist/typings/index.d.ts",
@@ -12,7 +12,7 @@
     "build": "npm run clean && npm run build:cjs && npm run build:umd",
     "build:cjs": "tsc",
     "build:umd": "webpack",
-    "deploy": "npm run build && npm publish -access public"
+    "deploy": "npm run build && npm publish -access public && npm install"
   },
   "pre-commit": [
     "lint"
@@ -30,6 +30,7 @@
   "devDependencies": {
     "@ridi/eslint-config": "^5.1.0",
     "@types/facebook-pixel": "0.0.19",
+    "@types/gtag.js": "0.0.3",
     "@types/jest": "^24.0.12",
     "@types/js-cookie": "^2.2.4",
     "@types/url-parse": "^1.4.1",
diff --git a/src/__tests__/index.ts b/src/__tests__/index.ts
index b14a483..43f53c3 100644
--- a/src/__tests__/index.ts
+++ b/src/__tests__/index.ts
@@ -1,4 +1,9 @@
-import { DeviceType, MainTrackerOptions, Tracker } from '../index';
+import {
+  DeviceType,
+  EventTrackerMethodNames,
+  MainTrackerOptions,
+  Tracker,
+} from '../index';
 import {
   BeaconTracker,
   GATracker,
@@ -7,7 +12,7 @@ import {
   TagManagerTracker,
   TwitterTracker,
 } from '../trackers';
-import { BaseTracker, EventTracker } from '../trackers/base';
+import { BaseTracker } from '../trackers/base';
 
 const ALL_TRACKERS = [
   BeaconTracker,
@@ -95,7 +100,7 @@ class TestableTracker extends Tracker {
 
   public mocking(
     trackers: Array<new (...args: any[]) => BaseTracker>,
-    methodName: keyof EventTracker,
+    methodName: EventTrackerMethodNames,
     mockImpl: () => void = () => true,
   ) {
     const mockingTargetTrackers = this.getTrackerInstances(...trackers);
@@ -106,7 +111,7 @@ class TestableTracker extends Tracker {
 
   public mockingAll(
     trackers: Array<new (...args: any[]) => BaseTracker>,
-    methodNames: Array<keyof EventTracker>,
+    methodNames: Array<EventTrackerMethodNames>,
     mockImpl: () => void = () => true,
   ) {
     return methodNames.map(m => this.mocking(trackers, m, mockImpl));
@@ -134,13 +139,12 @@ it('BeaconTracker sends PageView event with serviceProps', async () => {
   const sendBeaconMock = jest.fn();
 
   // @ts-ignore
-
   BeaconTracker.prototype.sendBeacon = sendBeaconMock;
   t.sendPageView(href, referrer);
 
   jest.runOnlyPendingTimers();
   expect(sendBeaconMock).toHaveBeenCalledWith(
-    'pageView',
+    'PageView',
     dummpyPageMeta,
     { prop1: 'value1', prop2: 'value2' },
     expect.any(Date),
@@ -222,7 +226,6 @@ it('GATracker should send pageview event', async () => {
   await t.initialize();
 
   // @ts-ignore
-
   window.ga = jest.fn();
   t.sendPageView(href, referrer);
 
@@ -234,7 +237,7 @@ it('GATracker should send pageview event', async () => {
   );
 });
 
-it('Test TwitterTracker', async () => {
+it.skip('Test TwitterTracker', async () => {
   const t = new TestableTracker({
     twitterOptions: {
       mainPid: 'mainPid',
@@ -246,9 +249,7 @@ it('Test TwitterTracker', async () => {
 
   t.mockingAll(ALL_TRACKERS.excludes(TwitterTracker), [
     'sendPageView',
-    'sendImpression',
     'sendSignUp',
-    'sendStartSubscription',
   ]);
 
   const trackPidMock = jest.fn();
@@ -257,28 +258,21 @@ it('Test TwitterTracker', async () => {
   const twitterTracker = t.getTrackerInstance(TwitterTracker);
 
   // @ts-ignore
-
   twitterTracker.twttr = { conversion: {} };
-
   // @ts-ignore
-
   twitterTracker.twttr.conversion.trackPid = trackPidMock;
 
   // @ts-ignore
-
   twitterTracker.twq = twqMock;
 
   await t.initialize();
 
   /* Need to disable flush throttling when sending event multiple times in one test cases */
   // @ts-ignore
-
   t.throttledFlush = t.flush.bind(t);
 
   t.sendPageView('href');
-  t.sendImpression();
-  t.sendSignUp();
-  t.sendStartSubscription();
+  t.sendSignUp('method');
 
   jest.runOnlyPendingTimers();
 
diff --git a/src/ecommerce/constants.ts b/src/ecommerce/constants.ts
new file mode 100644
index 0000000..53eee81
--- /dev/null
+++ b/src/ecommerce/constants.ts
@@ -0,0 +1,9 @@
+export enum Currency {
+  KRW = 'KRW',
+  USD = 'USD',
+}
+
+export enum ServiceType {
+  RIDIBOOKS = 'ridibooks',
+  RIDISELECT = 'ridiselect',
+}
diff --git a/src/ecommerce/index.ts b/src/ecommerce/index.ts
new file mode 100644
index 0000000..5c51ad6
--- /dev/null
+++ b/src/ecommerce/index.ts
@@ -0,0 +1,2 @@
+export * from './interface';
+export * from './models';
diff --git a/src/ecommerce/interface.ts b/src/ecommerce/interface.ts
new file mode 100644
index 0000000..2e4bc29
--- /dev/null
+++ b/src/ecommerce/interface.ts
@@ -0,0 +1,28 @@
+import { PurchaseInfo } from './models/transaction';
+import { Item, Promotion } from './models';
+
+export interface EcommerceTracker {
+  sendAddPaymentInfo(
+    paymentType: string,
+    purchaseInfo: PurchaseInfo,
+    ts?: Date,
+  ): void;
+
+  sendBeginCheckout(purchaseInfo: PurchaseInfo, ts?: Date): void;
+
+  sendPurchase(
+    transactionId: string,
+    purchaseInfo: PurchaseInfo,
+    ts?: Date,
+  ): void;
+
+  sendViewItem(items: Item[], ts?: Date): void;
+
+  sendAddToPreference(items: Item[], ts?: Date): void;
+
+  sendAddToNewBookNotification(items: Item[], ts?: Date): void;
+
+  sendViewContent(item: Item, ts?: Date): void;
+
+  sendViewItemList(items: Item[], ts?: Date): void;
+}
diff --git a/src/ecommerce/models/index.ts b/src/ecommerce/models/index.ts
new file mode 100644
index 0000000..f23b885
--- /dev/null
+++ b/src/ecommerce/models/index.ts
@@ -0,0 +1,2 @@
+export * from './item';
+export * from './promotion';
diff --git a/src/ecommerce/models/item.ts b/src/ecommerce/models/item.ts
new file mode 100644
index 0000000..5d91331
--- /dev/null
+++ b/src/ecommerce/models/item.ts
@@ -0,0 +1,23 @@
+import { Currency, ServiceType } from '../constants';
+import { Promotion } from './promotion';
+
+export interface Item extends Partial<Promotion> {
+  readonly item_id: string;
+  readonly item_name: string;
+  readonly item_repr_id?: string;
+  readonly item_repr_name?: string;
+  readonly service_type: ServiceType;
+  readonly author_id?: number;
+  readonly author: string;
+  readonly item_provider_id: number;
+  readonly item_provider_name: string;
+  readonly item_category: string;
+  readonly item_genre?: string;
+  readonly coupon?: string;
+  readonly discount?: number;
+  readonly price?: number;
+  readonly currency?: Currency;
+  readonly index?: number;
+  readonly item_list_id?: string;
+  readonly item_list_name?: string;
+}
diff --git a/src/ecommerce/models/promotion.ts b/src/ecommerce/models/promotion.ts
new file mode 100644
index 0000000..0ab86c0
--- /dev/null
+++ b/src/ecommerce/models/promotion.ts
@@ -0,0 +1,6 @@
+export interface Promotion {
+  readonly promotion_id: string;
+  readonly promotion_name: string;
+  readonly creative_name?: string;
+  readonly creative_slot?: number;
+}
diff --git a/src/ecommerce/models/transaction.ts b/src/ecommerce/models/transaction.ts
new file mode 100644
index 0000000..25b075c
--- /dev/null
+++ b/src/ecommerce/models/transaction.ts
@@ -0,0 +1,12 @@
+import { Currency } from '../constants';
+import { Item } from './item';
+
+export interface PurchaseInfo {
+  readonly coupon_name: string;
+  readonly coupon: number;
+  readonly cash: number;
+  readonly point: number;
+  readonly currency: Currency;
+  readonly value: number;
+  readonly items: Item[];
+}
diff --git a/src/index.ts b/src/index.ts
index 4311b49..3e890e1 100644
--- a/src/index.ts
+++ b/src/index.ts
@@ -4,10 +4,12 @@ import URL from 'url-parse';
 import {
   BeaconOptions,
   BeaconTracker,
+  EcommerceTracker,
   GAOptions,
   GATracker,
   GTagOptions,
   GTagTracker,
+  Item,
   KakaoOptions,
   KakaoTracker,
   PixelOptions,
@@ -18,6 +20,7 @@ import {
   TwitterTracker,
 } from './trackers';
 import { BaseTracker, EventTracker, PageMeta } from './trackers/base';
+import { PurchaseInfo } from './ecommerce/models/transaction';
 
 export enum DeviceType {
   PC = 'pc',
@@ -30,7 +33,7 @@ export type ServiceProp = Record<string, string>;
 export interface MainTrackerOptions {
   debug?: boolean;
   development?: boolean;
-  userId?: string;
+  uId?: number;
   deviceType: DeviceType;
   serviceProps?: ServiceProp;
   gaOptions?: GAOptions;
@@ -43,26 +46,29 @@ export interface MainTrackerOptions {
   twitterOptions?: TwitterOptions;
 }
 
-export interface ChangeableTrackerOptions {
-  userId?: string;
-  deviceType?: DeviceType;
-  serviceProps?: ServiceProp;
-}
+type ChangeableTrackerOptions = Pick<
+  MainTrackerOptions,
+  'uId' | 'deviceType' | 'serviceProps'
+>;
+
+type EventParameters =
+  | Parameters<EventTracker[keyof EventTracker]>
+  | Parameters<EcommerceTracker[keyof EcommerceTracker]>;
 
-type EventParameters = Parameters<EventTracker[keyof EventTracker]>;
+export type EventTrackerMethodNames =
+  | keyof EventTracker
+  | keyof EcommerceTracker;
 
 interface QueueItem {
-  consumerMethodName: keyof EventTracker;
+  consumerMethodName: EventTrackerMethodNames;
   eventParams: EventParameters;
   ts: Date;
 }
 
-function pushEventToQueue(consumerMethodName?: keyof EventTracker) {
-  return (
-    target: any,
-    propertyKey: keyof EventTracker,
-    descriptor: PropertyDescriptor,
-  ) => {
+function pushEventToQueue<T extends EventTrackerMethodNames>(
+  consumerMethodName?: T,
+) {
+  return (target: any, propertyKey: T, descriptor: PropertyDescriptor) => {
     consumerMethodName = consumerMethodName || propertyKey;
 
     const originalMethod = descriptor.value;
@@ -163,36 +169,64 @@ export class Tracker {
     }
   }
 
+  @pushEventToQueue()
+  public sendEvent(name: string, data: any = {}): EventParameters {
+    return [name, data];
+  }
+
   @pushEventToQueue()
   public sendPageView(href: string, referrer?: string): EventParameters {
-    const pageMeta = this.getPageMeta(href, referrer);
+    return [this.getPageMeta(href, referrer)];
+  }
 
-    return [pageMeta];
+  @pushEventToQueue()
+  public sendScreenView(
+    screenName: string,
+    previousScreenName: string,
+    referrer?: string,
+  ): EventParameters {
+    return [screenName, previousScreenName, referrer];
   }
 
   @pushEventToQueue()
-  public sendEvent(name: string, data: any = {}): EventParameters {
-    return [name, data];
+  public sendSignUp(method: string): EventParameters {
+    return [method];
+  }
+
+  @pushEventToQueue()
+  public sendLogin(method: string): EventParameters {
+    return [method];
+  }
+
+  @pushEventToQueue()
+  public sendBeginCheckout(purchaseInfo: PurchaseInfo): EventParameters {
+    return [purchaseInfo];
   }
 
   @pushEventToQueue()
-  public sendStartSubscription(): EventParameters {
-    return [];
+  public sendAddPaymentInfo(
+    paymentType: string,
+    purchaseInfo: PurchaseInfo,
+  ): EventParameters {
+    return [paymentType, purchaseInfo];
   }
 
   @pushEventToQueue()
-  public sendImpression(): EventParameters {
-    return [];
+  public sendPurchase(
+    transactionId: string,
+    purchaseInfo: PurchaseInfo,
+  ): EventParameters {
+    return [transactionId, purchaseInfo];
   }
 
   @pushEventToQueue()
-  public sendAddPaymentInfo(): EventParameters {
-    return [];
+  public sendViewItem(items: Item[], ts?: Date): EventParameters {
+    return [items];
   }
 
   @pushEventToQueue()
-  public sendSignUp(): EventParameters {
-    return [];
+  public sendViewContent(item: Item, ts?: Date): EventParameters {
+    return [item];
   }
 
   private initializedTrackers(): BaseTracker[] {
diff --git a/src/trackers/base.ts b/src/trackers/base.ts
index 42a3674..4fc3e4e 100644
--- a/src/trackers/base.ts
+++ b/src/trackers/base.ts
@@ -1,4 +1,5 @@
 import { DeviceType, MainTrackerOptions } from '../index';
+import { EcommerceTracker } from '../ecommerce';
 
 /* eslint-disable camelcase */
 export interface PageMeta {
@@ -14,44 +15,25 @@ export interface PageMeta {
 export interface EventTracker {
   sendPageView(pageMeta: PageMeta, ts?: Date): void;
 
-  sendEvent(name: string, data?: Record<string, unknown>, ts?: Date): void;
-
-  sendSignUp(args?: Record<string, unknown>, ts?: Date): void;
-
-  sendStartSubscription(args?: Record<string, unknown>, ts?: Date): void;
-
-  sendImpression(args?: Record<string, unknown>, ts?: Date): void;
-
-  sendAddPaymentInfo(args?: Record<string, unknown>, ts?: Date): void;
-}
-
-export abstract class BaseTracker implements EventTracker {
-  public mainOptions: MainTrackerOptions;
-
-  public abstract sendPageView(pageMeta: PageMeta, ts?: Date): void;
-
-  public abstract sendEvent(
-    name: string,
-    data?: Record<string, unknown>,
+  sendScreenView(
+    screenName: string,
+    previousScreenName: string,
+    referrer?: string,
     ts?: Date,
   ): void;
 
-  public abstract sendSignUp(args?: Record<string, unknown>, ts?: Date): void;
+  sendEvent(name: string, data?: Record<string, unknown>, ts?: Date): void;
 
-  public abstract sendImpression(
-    args?: Record<string, unknown>,
-    ts?: Date,
-  ): void;
+  sendSignUp(method: string, ts?: Date): void;
 
-  public abstract sendStartSubscription(
-    args?: Record<string, unknown>,
-    ts?: Date,
-  ): void;
+  sendLogin(method: string, ts?: Date): void;
+}
 
-  public abstract sendAddPaymentInfo(
-    args?: Record<string, unknown>,
-    ts?: Date,
-  ): void;
+// https://github.com/Microsoft/TypeScript/issues/4670#issuecomment-326585615
+export interface BaseTracker extends EventTracker, EcommerceTracker {}
+
+export abstract class BaseTracker implements EventTracker, EcommerceTracker {
+  public mainOptions: MainTrackerOptions;
 
   public abstract isInitialized(): boolean;
 
diff --git a/src/trackers/beacon.ts b/src/trackers/beacon.ts
index fc4b218..5d220af 100644
--- a/src/trackers/beacon.ts
+++ b/src/trackers/beacon.ts
@@ -3,6 +3,9 @@ import URL from 'url-parse';
 import { PVID, RUID } from '../uid';
 import { UIDFactory } from '../uid/factory';
 import { BaseTracker, PageMeta } from './base';
+import { PurchaseInfo } from '../ecommerce/models/transaction';
+import { Item, Promotion } from '../ecommerce/models';
+import { convertKeyToSnakeCase } from '../utils/util';
 
 export interface BeaconOptions {
   beaconSrc?: string;
@@ -15,10 +18,7 @@ export class BeaconTracker extends BaseTracker {
     use = true,
   }: BeaconOptions) {
     super();
-    this.options = {
-      beaconSrc,
-      use,
-    };
+    this.options = { beaconSrc, use };
   }
 
   private options: BeaconOptions;
@@ -54,14 +54,16 @@ export class BeaconTracker extends BaseTracker {
     if (ts == null) {
       ts = new Date();
     }
+
+    data = convertKeyToSnakeCase(data);
+
     const search = `?${URL.qs.stringify(pageMeta.query_params)}`;
 
     const log: BeaconLog = {
       event: eventName,
-      user_id: this.mainOptions.userId,
-      u_id: this.mainOptions.userId,
+      uid: this.mainOptions.uId,
       ruid: this.ruid.value,
-      pvid: this.pvid.value,
+      view_id: this.pvid.value,
       ...pageMeta,
       path: `${pageMeta.path}${search}`,
       data,
@@ -81,18 +83,13 @@ export class BeaconTracker extends BaseTracker {
 
   public sendPageView(pageMeta: PageMeta, ts?: Date): void {
     this.pvid = new UIDFactory(PVID).create();
-    this.sendBeacon(
-      BeaconEventName.PageView,
-      pageMeta,
-      this.mainOptions.serviceProps,
-      ts,
-    );
+    this.sendBeacon('PageView', pageMeta, this.mainOptions.serviceProps, ts);
     this.lastPageMeta = pageMeta;
   }
 
   public sendEvent(
     name: string,
-    data: Record<string, unknown> = {},
+    data: Record<string, any> = {},
     ts?: Date,
   ): void {
     if (this.lastPageMeta === undefined) {
@@ -104,29 +101,71 @@ export class BeaconTracker extends BaseTracker {
     this.sendBeacon(name, this.lastPageMeta, data, ts);
   }
 
-  public sendAddPaymentInfo(args?: Record<string, unknown>, ts?: Date): void {}
+  public sendLogin(method: string, ts?: Date): void {
+    this.sendEvent('Login', ts);
+  }
 
-  public sendImpression(args?: Record<string, unknown>, ts?: Date): void {}
+  public sendSignUp(method: string, ts?: Date): void {
+    this.sendEvent('SignUp', { method }, ts);
+  }
 
-  public sendSignUp(args?: Record<string, unknown>, ts?: Date): void {}
+  public sendScreenView(
+    screenName: string,
+    previousScreenName: string,
+    referrer?: string,
+    ts?: Date,
+  ): void {
+    this.sendEvent(
+      'ScreenView',
+      { screenName, previousScreenName, referrer },
+      ts,
+    );
+  }
 
-  public sendStartSubscription(
-    args?: Record<string, unknown>,
+  public sendAddPaymentInfo(
+    paymentType: string,
+    purchaseInfo: PurchaseInfo,
     ts?: Date,
-  ): void {}
-}
+  ): void {
+    this.sendEvent('AddPaymentInfo', { paymentType, ...purchaseInfo }, ts);
+  }
+
+  public sendBeginCheckout(purchaseInfo: PurchaseInfo, ts?: Date): void {
+    this.sendEvent('BeginCheckout', { ...purchaseInfo }, ts);
+  }
+
+  public sendAddToPreference(items: Item[], ts?: Date): void {
+    this.sendEvent('AddToPreference', { items }, ts);
+  }
+
+  public sendViewItem(items: Item[], ts?: Date): void {
+    this.sendEvent('ViewItem', { items }, ts);
+  }
 
-enum BeaconEventName {
-  PageView = 'pageView',
+  public sendViewContent(item: Item, ts?: Date): void {
+    this.sendEvent('ViewContent', { item }, ts);
+  }
+
+  public sendAddToNewBookNotification(items: Item[], ts?: Date): void {
+    this.sendEvent('AddToNewBookNotification', { items }, ts);
+  }
+
+  public sendPurchase(
+    transactionId: string,
+    purchaseInfo: PurchaseInfo,
+    ts?: Date,
+  ): void {
+    this.sendEvent('Purchase', { transactionId, ...purchaseInfo }, ts);
+  }
 }
+
 /* eslint-disable camelcase */
 interface BeaconLog extends PageMeta {
-  event: string;
-  user_id: string;
-  u_id: string;
-  ruid: string;
-  pvid: string;
-  data: Record<string, unknown>;
-  ts: number;
+  readonly event: string;
+  readonly uid: number;
+  readonly ruid?: string;
+  readonly view_id: string;
+  readonly data: Record<string, any>;
+  readonly ts: number;
 }
 /* eslint-enable camelcase */
diff --git a/src/trackers/ga.ts b/src/trackers/ga.ts
index c740479..d70652b 100644
--- a/src/trackers/ga.ts
+++ b/src/trackers/ga.ts
@@ -1,5 +1,7 @@
 import { loadGA } from '../utils/externalServices';
 import { BaseTracker, PageMeta } from './base';
+import { PurchaseInfo } from '../ecommerce/models/transaction';
+import { Item, Promotion } from '../ecommerce/models';
 
 interface GAFields extends UniversalAnalytics.FieldsObject {
   allowAdFeatures?: boolean;
@@ -11,6 +13,11 @@ export interface GAOptions {
   fields?: GAFields;
 }
 
+/**
+ * @deprecated Use GTagTracker Instead
+ * @see GTagTracker
+ */
+
 export class GATracker extends BaseTracker {
   constructor(private options: GAOptions) {
     super();
@@ -19,11 +26,12 @@ export class GATracker extends BaseTracker {
   private refinePath(originalPath: string): string {
     const refiners: Array<(path: string) => string> = [
       path => (this.options.pathPrefix ? this.options.pathPrefix + path : path),
-
-      // Pathname in some browsers doesn't start with slash character (/)
-      // Ref: https://app.asana.com/0/inbox/463186034180509/765912307342230/766156873493449
-
-      path => (path.startsWith('/') ? path : `/${path}`),
+      path =>
+        path.startsWith('/')
+          ? path
+          : `/${
+              path // Ref: https://app.asana.com/0/inbox/463186034180509/765912307342230/766156873493449 // Pathname in some browsers doesn't start with slash character (/)
+            }`,
     ];
 
     return refiners.reduce((value, refiner) => refiner(value), originalPath);
@@ -73,14 +81,21 @@ export class GATracker extends BaseTracker {
     ga('send', fields);
   }
 
-  public sendAddPaymentInfo(args?: Record<string, unknown>, ts?: Date): void {}
+  public sendSignUp(method: string, ts?: Date): void {}
+
+  public sendAddPaymentInfo(
+    paymentType: string,
+    purchaseInfo: PurchaseInfo,
+    ts?: Date,
+  ): void {}
 
-  public sendImpression(args?: Record<string, unknown>, ts?: Date): void {}
+  public sendViewItem(items: Item[], ts?: Date): void {}
 
-  public sendSignUp(args?: Record<string, unknown>, ts?: Date): void {}
+  public sendViewItemList(items: Item[], ts?: Date): void {}
 
-  public sendStartSubscription(
-    args?: Record<string, unknown>,
+  public sendPurchase(
+    transactionId: string,
+    purchaseInfo: PurchaseInfo,
     ts?: Date,
   ): void {}
 }
diff --git a/src/trackers/gtag.ts b/src/trackers/gtag.ts
index 865fe40..73cde3f 100644
--- a/src/trackers/gtag.ts
+++ b/src/trackers/gtag.ts
@@ -1,8 +1,12 @@
 import { loadGTag } from '../utils/externalServices';
 import { BaseTracker, PageMeta } from './base';
+import { PurchaseInfo } from '../ecommerce/models/transaction';
+import { Item } from '../ecommerce/models';
 
 export interface GTagOptions {
   trackingId: string;
+  autoPageView?: boolean;
+  defaultCurrency?: string;
 }
 
 declare global {
@@ -14,35 +18,96 @@ declare global {
 export class GTagTracker extends BaseTracker {
   constructor(private options: GTagOptions) {
     super();
+    options.defaultCurrency = options.defaultCurrency || 'KRW';
   }
 
-  private tagCalled = false;
-
   public async initialize(): Promise<void> {
     await loadGTag(this.options.trackingId);
-    this.tagCalled = true;
+    gtag('config', this.options.trackingId, {
+      send_page_view: this.options.autoPageView,
+      // eslint-disable-next-line prettier/prettier
+      user_id: this.mainOptions.uId?.toString(),
+    });
+    gtag('set', { currency: this.options.defaultCurrency });
   }
 
   public isInitialized(): boolean {
-    return this.tagCalled;
+    return typeof gtag === 'function';
   }
 
-  public sendPageView(pageMeta: PageMeta, ts?: Date): void {}
+  public sendPageView(pageMeta: PageMeta, ts?: Date): void {
+    gtag('event', 'page_view', {
+      page_location: pageMeta.href,
+      page_path: pageMeta.path,
+      page_title: pageMeta.page,
+    });
+  }
 
   public sendEvent(
     name: string,
     data?: Record<string, unknown>,
     ts?: Date,
-  ): void {}
+  ): void {
+    gtag('event', name, data);
+  }
+
+  public sendAddPaymentInfo(
+    paymentType: string,
+    purchaseInfo: PurchaseInfo,
+    ts?: Date,
+  ): void {
+    gtag('event',
+      'add_payment_info',
+      {
+      payment_type: paymentType,
+        ...purchaseInfo,
+        coupon: purchaseInfo.coupon_name,
+      });
+  }
+
+  public sendSignUp(method: string, ts?: Date): void {
+    gtag('event', 'sign_up', { method });
+  }
+
+  public sendScreenView(
+    screenName: string,
+    previousScreenName: string,
+    referrer?: string,
+    ts?: Date,
+  ): void {
+    gtag('event', 'screen_view', { screen_name: screenName });
+  }
+
+  public sendViewItem(items: Item[], ts?: Date): void {
+    gtag('event', 'view_item', { items });
+  }
+
+  public sendViewItemList(items: Item[], ts?: Date): void {
+    gtag('event', 'view_item_list', { items });
+  }
 
-  public sendAddPaymentInfo(args?: Record<string, unknown>, ts?: Date): void {}
 
-  public sendImpression(args?: Record<string, unknown>, ts?: Date): void {}
+  public sendPurchase(
+    transactionId: string,
+    purchaseInfo: PurchaseInfo,
+    ts?: Date,
+  ): void {
+    gtag('event', 'purchase', {
+      transaction_id: transactionId,
+      ...purchaseInfo,
+    });
+  }
 
-  public sendSignUp(args?: Record<string, unknown>, ts?: Date): void {}
+  public sendBeginCheckout(purchaseInfo: PurchaseInfo, ts?: Date): void {
+    gtag('event', 'begin_checkout', {
+      ...purchaseInfo,
+      coupon: purchaseInfo.coupon_name,
+    });
+  }
 
   public sendStartSubscription(
     args?: Record<string, unknown>,
     ts?: Date,
   ): void {}
+
 }
diff --git a/src/trackers/index.ts b/src/trackers/index.ts
index 192278e..93975e1 100644
--- a/src/trackers/index.ts
+++ b/src/trackers/index.ts
@@ -5,3 +5,4 @@ export * from './tagmanager';
 export * from './gtag';
 export * from './kakao';
 export * from './twitter';
+export * from '../ecommerce';
diff --git a/src/trackers/kakao.ts b/src/trackers/kakao.ts
index 7147d0c..693fdf4 100644
--- a/src/trackers/kakao.ts
+++ b/src/trackers/kakao.ts
@@ -1,5 +1,7 @@
 import { loadKakao } from '../utils/externalServices';
 import { BaseTracker, PageMeta } from './base';
+import { Item, Promotion } from '../ecommerce/models';
+import { PurchaseInfo } from '../ecommerce/models/transaction';
 
 declare let kakaoPixel: (trackingId: string) => KakaoPixel;
 
@@ -39,22 +41,25 @@ export class KakaoTracker extends BaseTracker {
     this.tracker.pageView();
   }
 
-  public sendSignUp(args?: Record<string, unknown>, ts?: Date): void {
+  public sendSignUp(method: string, ts?: Date): void {
     this.tracker.completeRegistration();
   }
 
-  public sendStartSubscription(
-    args?: Record<string, unknown>,
+  public sendAddPaymentInfo(
+    paymentType: string,
+    purchaseInfo: PurchaseInfo,
     ts?: Date,
-  ): void {
-    this.tracker.signUp();
-  }
+  ): void {}
 
-  public sendImpression(args?: Record<string, unknown>, ts?: Date): void {
-    this.tracker.viewContent();
-  }
+  public sendViewItem(items: Item[], ts?: Date): void {}
 
-  public sendAddPaymentInfo(args?: Record<string, unknown>, ts?: Date): void {}
+  public sendViewItemList(items: Item[], ts?: Date): void {}
+
+  public sendPurchase(
+    transactionId: string,
+    purchaseInfo: PurchaseInfo,
+    ts?: Date,
+  ): void {}
 
   public sendEvent(
     name: string,
diff --git a/src/trackers/pixel.ts b/src/trackers/pixel.ts
index 14f48d6..821f069 100644
--- a/src/trackers/pixel.ts
+++ b/src/trackers/pixel.ts
@@ -1,5 +1,7 @@
 import { loadPixel } from '../utils/externalServices';
 import { BaseTracker, PageMeta } from './base';
+import { Item, Promotion } from '../ecommerce';
+import { PurchaseInfo } from '../ecommerce/models/transaction';
 
 export interface PixelOptions {
   pixelId: string | string[];
@@ -40,20 +42,27 @@ export class PixelTracker extends BaseTracker {
     }
   }
 
-  public sendAddPaymentInfo(args?: Record<string, unknown>, ts?: Date): void {}
-
   public sendEvent(
     name: string,
     data?: Record<string, unknown>,
     ts?: Date,
   ): void {}
 
-  public sendImpression(args?: Record<string, unknown>, ts?: Date): void {}
+  public sendSignUp(method: string, ts?: Date): void {}
+
+  public sendAddPaymentInfo(
+    paymentType: string,
+    purchaseInfo: PurchaseInfo,
+    ts?: Date,
+  ): void {}
+
+  public sendViewItem(items: Item[], ts?: Date): void {}
 
-  public sendSignUp(args?: Record<string, unknown>, ts?: Date): void {}
+  public sendViewItemList(items: Item[], ts?: Date): void {}
 
-  public sendStartSubscription(
-    args?: Record<string, unknown>,
+  public sendPurchase(
+    transactionId: string,
+    purchaseInfo: PurchaseInfo,
     ts?: Date,
   ): void {}
 }
diff --git a/src/trackers/tagmanager.ts b/src/trackers/tagmanager.ts
index 4a72f3e..7e79bbb 100644
--- a/src/trackers/tagmanager.ts
+++ b/src/trackers/tagmanager.ts
@@ -2,6 +2,9 @@ import { MainTrackerOptions } from '..';
 
 import { loadTagManager } from '../utils/externalServices';
 import { BaseTracker, PageMeta } from './base';
+import { Item } from '../ecommerce';
+import { PurchaseInfo } from '../ecommerce/models/transaction';
+import { convertKeyToSnakeCase } from '../utils/util';
 
 export interface TagManagerOptions {
   trackingId: string;
@@ -28,11 +31,18 @@ export class TagManagerTracker extends BaseTracker {
     return window.dataLayer;
   }
 
+  private pushDataLayer(data: Record<string, any>): void {
+    this.dataLayer.push(data);
+  }
+
   public setMainOptions(newOptions: MainTrackerOptions): void {
-    super.setMainOptions(newOptions);
+    if (this.mainOptions) {
+      this.sendEvent('OptionsChanged', newOptions);
+    } else {
+      this.pushDataLayer(newOptions);
+    }
 
-    this.pushDataLayer(newOptions);
-    this.sendEvent('Options Changed', newOptions);
+    super.setMainOptions(newOptions);
   }
 
   public async initialize(): Promise<void> {
@@ -41,37 +51,79 @@ export class TagManagerTracker extends BaseTracker {
     this.tagCalled = true;
   }
 
+  public sendEvent(
+    name: string,
+    data: Record<string, any> = {},
+    ts?: Date,
+  ): void {
+    data = convertKeyToSnakeCase(data);
+    this.pushDataLayer({ event: name, event_params: data, ts });
+  }
+
   public isInitialized(): boolean {
     return this.tagCalled;
   }
 
   public sendPageView(pageMeta: PageMeta, ts?: Date): void {
-    this.sendEvent('Page View', pageMeta, ts);
+    this.sendEvent('PageView', { ...pageMeta }, ts);
   }
 
-  public sendEvent(
-    name: string,
-    data: Record<string, any> = {},
+  public sendScreenView(
+    screenName: string,
+    previousScreenName: string,
+    referrer?: string,
     ts?: Date,
   ): void {
-    this.dataLayer.push({
-      event: name,
-      data,
-    });
+    this.sendEvent(
+      'ScreenView',
+      { screenName, previousScreenName, referrer },
+      ts,
+    );
   }
 
-  private pushDataLayer(data: Record<string, any>): void {
-    this.dataLayer.push(data);
+  public sendSignUp(method: string, ts?: Date): void {
+    this.sendEvent('SignUp', { method }, ts);
   }
 
-  public sendAddPaymentInfo(args?: Record<string, unknown>, ts?: Date): void {}
+  public sendLogin(method: string, ts?: Date): void {
+    this.sendEvent('Login', { method }, ts);
+  }
 
-  public sendImpression(args?: Record<string, unknown>, ts?: Date): void {}
+  public sendBeginCheckout(purchaseInfo: PurchaseInfo, ts?: Date): void {
+    this.sendEvent('BeginCheckout', { ...purchaseInfo }, ts);
+  }
 
-  public sendSignUp(args?: Record<string, unknown>, ts?: Date): void {}
+  public sendAddPaymentInfo(
+    paymentType: string,
+    purchaseInfo: PurchaseInfo,
+    ts?: Date,
+  ): void {
+    this.sendEvent('AddPaymentInfo', { paymentType, ...purchaseInfo }, ts);
+  }
+
+  public sendAddToPreference(items: Item[], ts?: Date): void {
+    this.sendEvent('AddToPreference', { items }, ts);
+  }
 
-  public sendStartSubscription(
-    args?: Record<string, unknown>,
+  public sendAddToNewBookNotification(items: Item[], ts?: Date): void {
+    this.sendEvent('AddToNewBookNotification', { items }, ts);
+  }
+
+  public sendViewItem(items: Item[], ts?: Date): void {
+    this.sendEvent('ViewItem', { items }, ts);
+  }
+
+  public sendViewContent(item: Item, ts?: Date): void {
+    this.sendEvent('ViewContent', { item }, ts);
+  }
+
+  public sendViewItemList(items: Item[], ts?: Date): void {}
+
+  public sendPurchase(
+    transactionId: string,
+    purchaseInfo: PurchaseInfo,
     ts?: Date,
-  ): void {}
+  ): void {
+    this.sendEvent('Purchase', { transactionId, ...purchaseInfo }, ts);
+  }
 }
diff --git a/src/trackers/twitter.ts b/src/trackers/twitter.ts
index 8dbcc6e..4dd4987 100644
--- a/src/trackers/twitter.ts
+++ b/src/trackers/twitter.ts
@@ -3,6 +3,8 @@ import {
   loadTwitterUniversal,
 } from '../utils/externalServices';
 import { BaseTracker, PageMeta } from './base';
+import { Item } from '../ecommerce';
+import { PurchaseInfo } from '../ecommerce/models/transaction';
 
 declare let twq: any;
 declare let twttr: any;
@@ -14,6 +16,9 @@ export interface TwitterOptions {
   impressionPid: string;
 }
 
+/**
+ * @deprecated Use GTM provided tag
+ */
 export class TwitterTracker extends BaseTracker {
   constructor(private options: TwitterOptions) {
     super();
@@ -35,39 +40,36 @@ export class TwitterTracker extends BaseTracker {
     return typeof this.twq === 'function' && typeof this.twttr === 'object';
   }
 
+  public sendEvent(
+    name: string,
+    data?: Record<string, unknown>,
+    ts?: Date,
+  ): void {}
+
   public sendPageView(pageMeta: PageMeta, ts?: Date): void {
     this.twq('track', 'pageView');
   }
 
-  public sendSignUp(args?: Record<string, unknown>, ts?: Date): void {
+  public sendSignUp(method: string, ts?: Date): void {
     this.twttr.conversion.trackPid(this.options.booksSignUpPid, {
       tw_sale_amount: 0,
       tw_order_quantity: 0,
     });
   }
 
-  public sendStartSubscription(
-    args?: Record<string, unknown>,
+  public sendAddPaymentInfo(
+    paymentType: string,
+    purchaseInfo: PurchaseInfo,
     ts?: Date,
-  ): void {
-    this.twttr.conversion.trackPid(this.options.selectStartSubscriptionPid, {
-      tw_sale_amount: 0,
-      tw_order_quantity: 0,
-    });
-  }
+  ): void {}
 
-  public sendImpression(args?: Record<string, unknown>, ts?: Date): void {
-    this.twttr.conversion.trackPid(this.options.impressionPid, {
-      tw_sale_amount: 0,
-      tw_order_quantity: 0,
-    });
-  }
+  public sendViewItem(items: Item[], ts?: Date): void {}
 
-  public sendAddPaymentInfo(args?: Record<string, unknown>, ts?: Date): void {}
+  public sendViewItemList(items: Item[], ts?: Date): void {}
 
-  public sendEvent(
-    name: string,
-    data?: Record<string, unknown>,
+  public sendPurchase(
+    transactionId: string,
+    purchaseInfo: PurchaseInfo,
     ts?: Date,
   ): void {}
 }
diff --git a/src/utils/util.ts b/src/utils/util.ts
new file mode 100644
index 0000000..5f65c60
--- /dev/null
+++ b/src/utils/util.ts
@@ -0,0 +1,5 @@
+import _ from 'lodash';
+
+export function convertKeyToSnakeCase(obj: Record<any, any>): Record<any, any> {
+  return _.mapKeys(obj, (v, k) => _.snakeCase(k));
+}