How much thread drift is permitted? Does it depend on which forum the thread is in? More thread drift in the community forum less thread drift in special topic forums?
My personal feeling is that it's okay, as long as it's cool with the topic starter. I can see how someone who started a topic could get upset if they felt their topic was being hijacked. But even then, a certain amount of thread drift seems okay, as long as the thread eventually drifts back to the main topic.
It's in my nature to drift off topic, but I usually can bring it back to the main topic. And there are some great extended threads that started because of a simple question and then wandered off into a good discussion about other things. So I'd like to think those threads can spontaneously occur.