Facebook Page Administration
500,743 websites

Facebook Page Administration is free to use

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

Identifies administrators for a page which will be able publish data to your wall if you like any content within this page.

VS

Twitter Button
837,185 websites

Twitter Button is free to use

https://about.twitter.com/resources/buttons#tweet

The Tweet Button is a small widget which allows visitors to share content and connect on Twitter.

Market Share by Top Websites

1 Twitter Button is leading in Top 1M Sites and The Entire Web.

2 Facebook Page Administration is leading in Top 10K Sites and Top 100K Sites.

Websites Categories

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

2 Facebook Page Administration hasn't got a lead over Twitter Button in any websites category.

Geography

1 Twitter Button is leading in most countries, including Japan, United States, France, United Kingdom and 84 other countries.

2 Facebook Page Administration is leading in Brazil, Germany, Australia, Vietnam and 71 other countries.