I'm (thankfully) out of date on Facebook marketing tactics, but gating content behind Likes and Invited Friend Counts is standard - there are even plenty of sweepstakes to win just for consenting to being shown a like button. Generally speaking, the content behind these gates is a single payoff - a little nibble of digital content. Companies love that trade for ears to promote content to, "like" being a friendly euphemism for "subscribe" and all.
I'm sure it's been tried, but it might be interesting to check Like/Follow persistence in exchange for long-term access to content and services. "Have a twitter account following ours? You're in!"