Not really, I'm not really good at it. I think my questions are too heady so people are bored and uninterested. I have had a few that did really well in the topic of entertainment. However, one was closed by HP for encouraging too much conversation or something. I still don't understand that but it's all good. I'm not good at Q&A and need to put the bulk of my energy in writing quality hubs where I get real organic traffic and earnings. Q&A is for fun so I don't expect a lot of traffic to them. However, they can generate interest from and networking with other hubbers which can potentially increase internal traffic.
Edit: No, I don't get organic traffic from those that did well; it was all internal. Some of my old ones get an organic hit once in a while.