I'll start off with my answer.
I joined clraik mainly because of the rules -- I dislike forums that tolerate cyber bullying or anything along those lines, which gave me a good impression that the community is very mature/pleasant, and I was right. Next one would probably be buying/selling stuff. Though, I don't really buy and sell stuff a lot -- I only get $ to buy stuff by selling my very own main account which only happens when I want to make a new one. And the last one, the programs, it didn't really affect my decision of joining though, only a little bit.