Not sure. I always answer and ask. Life is full of questions. And even though I think I know everything at times. The world still surprises me with questions. But thanks to fluther I can usually find the answer.
I answer questions where I have something to add to the discussion already there. I read most questions and ask a few that I think will contribute to the process here on fluther.
There are a lot of times when that would describe me. I read some Q & A threads and where I have nothing to add (or detract), then I sprinkle GQ / GA as I deem appropriate, and move on.