Yes, I'm on it and I interact with it a lot (writing lots of messages)
Yes, I'm on it, but I interact only every here and now with it (writing every now and then in there)
Yes, I'm on it, but I prefer to lurk (not writing much, if anything at all)
No, I'm not on it, but I'd like to join (you're welcome if you've EVER pledged, even if you currently aren't!)
No, I'm not on it, and I have no interest in joining