Facebook Social Graph
271,051 websites

Facebook Social Graph is free to use

https://www.facebook.com/about/graphsearch

Now you can find more of what you're looking for on Facebook and discover fun connections between people, places and things.

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Google +1 Button
597,414 websites

Google +1 Button is free to use

https://developers.google.com/+/web/+1button/

Let visitors recommend your content on Google Search and share it on Google+.

Market Share by Top Websites

1 Google +1 Button is leading in Top 100K Sites, Top 1M Sites and The Entire Web.

2 Facebook Social Graph is leading in Top 10K Sites.

Websites Categories

1 Google +1 Button has better usage coverage in more websites categories. Including Computers Electronics & Technology, Arts & Entertainment, Science & Education, Travel & Tourism and 19 other categories.

2 Facebook Social Graph is leading in Community & Society.

Geography

1 Google +1 Button is leading in most countries, including Japan, France, Italy, Russia and 152 other countries.

2 Facebook Social Graph is leading in United States, Australia, New Zealand, Finland and 4 other countries.