I tend to just give it away when I have parties in my apartment. I just like to see what people think of it. I love the idea of making something that makes people go woah! and gets them drunk.
Probably not a good thing, but I think the reasoning in my head is that making beer that people will talk about and love to drink covers the cost of all the brews I have to make to keep up with them drinking it :-D
Also, in my apartment my roomate and I have a jar for beer money. Most of my friends put money in it when they feel they need to pay me and when they have cash on them. I never ask, the jar just fills itself. The only time I say something is the first time someone asks if I want some money for drinks. I point to the jar and say pay me when you feel like and however much you feel, I trust you will throw in what you feel is right.
Of course for big parties we have to hide that cash (I don't trust EVERYONE), but when it's just the regulars drinking here it works out nicely.