I met Master on IRC of all places. We talked for a few weeks then met in real life. We have been married 8 years. We are a poly couple and have met other sub/ slaves online and some were less then truthful about things and some were delightful. Anyone can be anything they want online. So it is hard to tell from just chatting online if things will work out.
I was lucky with Master but before him I had met some that were good Doms and some not. Sometimes you cannot tell if you are compatible with someone until you meet face to face. I think it is 50/50 either way.