Facebook fan gain method?

Sending invitations is died before several moths ago. But I saw still lots of freelancers are providing their service continuously without having problem or at least I didn't see any negative feedback for their service.
So does any one know any working method to gather fans in these days?
Any help really appreciated.

I'd also be interested in the methods of gaining facebook fans different people are using out there. Twitter is very easy, Facebook, not so much