lexipixel - 3:55 am on Jul 7, 2011 (gmt 0)
If done right, you can get fans for a cheap as $0.01 per fan (I know this because I teach a course on facebook marketing).
What's to stop the $0.01 "fans" from un-liking you?
As for the "contest" route, that is a horrible idea because for one, most likely they are not targeted fans and another thing is most fans that join a fan page via. a contest usually "UNLIKE" that page once the contest is over since they are not interested in the page, only what you were offering for free.
I completely disagree.
If your offer is "We will randomly pick (1) Facebook Fan each weeks to win ___(whatever)___" they would not un-like you just because they didn't win the particular weeks the Liked you.
I see many commercial operations that post things on their website saying check our Facebook page for weekly specials -- this drives traffic to Facebook, which in-turn gets them additional exposire from socially networked friends of the original "Liker" -- which results in additional traffic back to the website.
Many businesses post "Mention Promo code: FB727X" of similar verbiage on Facebook -- are you saying this against FB's TOS ? If so, please post a reference to that clause of the TOS.