Same answer you'd expect from anyone: people with similar interests. Add me if you like, but only if you plan on actually talking to me. I don't want 12,000 friends. To that end, if someone adds me and it isn't immediately clear that they are worth of my time (they send a message first, they seem cool, or we know each other in person), I will probably deny their request. 95% of the time I deny bands too.