The difficulties with mainstream erotica is that there really is SO MUCH out there, the good news with it is that its out there because of DEMAND. My "mainstream babysitter" erotica has sold double every other piece I've offered.
Kinks are an entirely different beast. There are people out them that want them - but there are less of them. The good news with writing "kink" erotica is that you reach more people, and you may be up against less competition, plus if you enjoy it the variety will help you from keeping burned out. The other problem with a kink - as shown with the Paypal and Bookstrand removal of Pseudo-incest, "rape", etc, is that it may meet opposition from society. Telling someone you write erotica is one thing - telling them you write rape stories may be quite another.
In the end my mainstreams bring in my paycheck - my kinks are fun and are an added bonus. :) I'm curious how everyone else fairs with their kinks?
Do you write solely within that kink? I've heard it said over and over to spread yourself out - do you believe in that? Write me comment and tell me your thoughts!