Thu May 23, 2013 3:26 am
It's probably possible but would be rather convoluted.
Before someone can like your page they have to be logged into Facebook, before they can be logged into Facebook they have to have access to it (via walled garden).
So you'd essentially need to give your users free access to Facebook 24/7 without logging in to force them to like your page before getting online normally.
You'd also need a way (probably a Facebook app of some sort) to pass info on each user back so you knew if they had liked the page.
All in all it would be possible but I don't think the amount of time it takes would be worth the effort.