Since Facebook has switched to the ‘Like’ button it seems that people, including myself, are leery of getting rid of the word Fan when promoting pages. I just saw a sentence that said “Make sure you hit the ‘Like’ button to become a fan of insert page name!”
Facebook has dropped the word fan from all pages except on the insight page for admins, and with all the open source Facebook buttons it seems like the Like Button has taken over the web. However, since so many people are still using the phrase Become a Fan did Facebook make a mistake with the button change? Could they co-exist?