Facebook Social Plugins
3,185,744 websites

Facebook Social Plugins is free to use

http://developers.facebook.com/docs/plugins/

See what your Facebook friends have liked, shared, or commented on across the Web. This includes all variations of Like, Share and Follow Buttons, Embedded Posts, Comments, Activity Feed, Recommendations Feed, Recommendations Bar, Like Box...

VS

Free PageRank
195 websites

Free PageRank is free to use

http://www.prchecker.info/

Page Rank Checker is a completely Free tool to check Google PR, page rank of your web site easily and possibly display your Google PageRank on your web ...

Market Share by Top Websites

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

2 In terms of market share, Free PageRank is clearly lagging behind, losing to Facebook Social Plugins in all segments.

Websites Categories

1 Facebook Social Plugins has better usage coverage in more websites categories. Including Computers Electronics & Technology, Arts & Entertainment, Science & Education, Food & Drink and 20 other categories.

2 Free PageRank hasn't got a lead over Facebook Social Plugins in any websites category.

Geography

1 Facebook Social Plugins is leading in most countries, including United States, Japan, France, Italy and 162 other countries.

2 Free PageRank hasn't got a lead over Facebook Social Plugins in any country.