Facebook has introduced a new design feature. It is replacing the "Become a fan" button with "Like" button.
There is now more than one fan metric. There is a new social graph metric associated with the page, displaying how many of your personal friends like the brand too.
The purpose of the change was to strengthen the interaction between regular users and brands. Supposedly, the "Like" button has performed twice as well as the "Become a fan" button.
Note: The news of this change first broke last month on Clickz based on a confidential letter to the press.