Facebook renamed its “Become a fan” button texts to “like” recently. The change has been done to all the pages 2 days earlier and the notification is now at facebook users profile page. The new like button spreads the news you receive from the pages you liked, to your friends as well. Do check out the Instant Personalization feature added standing the row as a new feature from facebook. Whenever you visit a website that have facebook personalized features added then you will get a notification in the header bar to connect the site features with your facebook account. This will allow you to share documents, musics, movies, and so many interesting contents with your Facebook friends instantly.
Microsoft Docs, Pandora, Slate and Yelp are such services that you can see with the personalization effect when you logged into your facebook account with another window or tab. You can read more info at Facebook Tour Page.