It is recommended by W3C to use a general type for the font-family property.

Author: vanderhoorn

styles/token-input-facebook.css

@@ -7,7 +7,7 @@ ul.token-input-list-facebook {
     border: 1px solid #8496ba;
     cursor: text;
     font-size: 12px;
-    font-family: Verdana;
+    font-family: Verdana, sans-serif;
     min-height: 1px;
     z-index: 999;
     margin: 0;
@@ -80,7 +80,7 @@ div.token-input-dropdown-facebook {
     border-bottom: 1px solid #ccc;
     cursor: default;
     font-size: 11px;
-    font-family: Verdana;
+    font-family: Verdana, sans-serif;
     z-index: 1;
 }