I can't seem to find a way to find out the chronological order specific users 'liked' a page.The main purpose would be to award say the 5000th user that joined my page. However, as much data as possible is also beneficial - be it acquired via standard means (via Facebook site), or the Facebook API (which I currently know nothing about).
Sort fans of a Facebook page by join date
facebook
Facebook terms prohibit you from providing prizes for people fanning your page - you have to offer the bonus as a sweepstakes that is accessible to all fans of your page.For this reason, they don't let you see the order in which fans joined your page.