I enjoy both the comments and the ratings. They are a big ego boost too. What I don't get is why so many people leave blank comments =/ It's not that hard to write a short nice message, is it? Of course, if you don't have anything good to say, don't say nothing at all. But then, if you didn't have anything good to say, you wouldn't rate a picture 10, would you?
Anyway, it is always nice to read the comments. Also, I like to check out how many times my pictures have been viewed. Even if there are not new comments, it shows they caught peoples eyes... at least enough for them to go check it out.
On the other hand, I've thanked some of the comments on my own comment board and others on PM. I think I'll start thanking all of them on PM, since people were nice enough to send a "custom" comment aswell =)
PS: NJQT's nipples... who in here HASN'T imagined them covered in whipped cream? mmm yummy =P