I picked up Black Goat today (Save Dark Pharaoh, which I'm waiting for the reprint, I'm not caught up on Small Box!), and started looking through it. Now I've heard previously through comments that people don't join the Cult often. I'd assumed it was because most people decided it wasn't worth the risk. Then I looked through the cards. There are, by my count, a grand total of just FOUR oppotunities to join the Cult - 1 at the Unvisted Isle and Black Cave, and 2 at the woods. With just the base game and the expansion mixed togeether, that's a 1/10 chance at just two locations, and a 1/5 chance at 1 location. I don't think I normally have an encounter at a location 5 times in a game, much less 10. That's ridiculously low - that's way lower than even drawing the Act cards in KiY (and those are SUPPOSED to be really rare). Even if you force them to join when they draw the card, it's so rare that it's almost impossible.
So, I think I've hit upon a house-rules solution to make it slightly less rare. Whenever you defeat a Cultist (or a monster treated as a Cultist), you may voluntarily join the Cult or pass a Will(+0) Check or avoid being forced to join the cult. The in-story idea is that the Cultist is impressed with your fighting prowess, and makes you an offer to become one of the Thousand. That should make it a bit more likely to get a chance to join the Cult, and actually make all these cult encounter cards and corruption cards worth something.
What do you guys think? Do you just ignore the Cult mostly?
I like your idea for giving the Cult some teeth and actually getting out there on a robust marketing and recruitment scheme. 

