Facebook Connect
4,940,298 websites

Facebook Connect is free to use

http://developers.facebook.com/connect.php

Facebook Connect allow users to connect their Facebook identity, friends and, privacy to any website. Facebook Connect is Facebook's first attempt to allow access to Facebook user data outside of Facebook itself. The company is describing ...

VS

Zendesk
764,132 websites

Zendesk offers both free and paid options

http://zendesk.com/

Zendesk provides an integrated on-demand helpdesk - customer support portal solution based on the latest Web 2.0 technologies and design philosophies. The product has an elegant, minimalist design implemented in Ruby on Rails and provide...

Market Share by Top Websites

1 Facebook Connect is leading in Top 10K Sites, Top 100K Sites, Top 1M Sites and The Entire Web.

2 In terms of market share, Zendesk is clearly lagging behind, losing to Facebook Connect in all segments.

Websites Categories

1 Facebook Connect has better usage coverage in more websites categories. Including Computers Electronics & Technology, Arts & Entertainment, Science & Education, Lifestyle and 18 other categories.

2 Zendesk is leading in Games and Adult.

Geography

1 Facebook Connect is leading in most countries, including United States, Japan, United Kingdom, Brazil and 162 other countries.

2 Zendesk hasn't got a lead over Facebook Connect in any country.