IME it's always been pretty common. The flexible scheduling makes it easy to fit in around a full time job and not being financially dependent upon domination gives you a lot of flexibility in how you run your business. High rates/extensive screening might scare away clients -- but who gives a shit if the money is basically just bonus cash and you don't have time to be sessioning constantly anyway? By the same token, go ahead and fire that mildly annoying regular who hasn't done anything egregious. You'll be more enthused about the sessions you do take so it works out well in the long run.