1) It's threaded, so nobody has to reply to your comment if they don't want to. It's _much_ harder to drag a whole comments section off-topic over here than one somewhere without threaded comments.
2) My daily links posts are for people to discuss interesting things in, and generally keep me distracted at work*. If you're having fun in the comments section, and nobody is being a jerk, then you are an awesome person and I love you.
In summary - so long as you're not being mean to anyone** treat the comments as an open discussion forum. I love the tiny bit of community here, it's awesome.
*Also, for people to verify the truth of them, and tell me when I've fallen for something which isn't even remotely true. This is a very useful service you provide.
**Bearing in mind the rules about pedantic grammar niggling, and spoilers
Original post on Dreamwidth - there are comments there.