It's different for everyone. Some think it is and edit the comments, others don't care and just reply. Just do whatever you want.

-Tor

Yah, I do anyway. 'Cause it's a lot like when you wonder if anyone reads your blog, it's like, "Does this person know or care that I read their blog?"

I do it in my topics, like most people, to let 'em know that their support is appreciated.

It makes it less creepy. I'll only edit people's comments to annoy them.

Usually though, it's more of to argue with the opinions of the people who post. They're never flame wars though.