Photostar has a good idea for the Art Charts.

I see lots of really good artist that get hardly any comments at all. One of the hard parts is just getting peoples attention to take a look and then take the time to leave a comment.. Looking at pages of stuff in a short period of time sometimes its hard to leave more then a short comment. I think leaving a comment to say hi I stopped by and enjoyed looking at your artwork is important. 

Personally - I do not let it bother me or affect how I want to comment to other people. I appreciate everyone who comes by and looks at my images and leaves a comment. Those that leave a bit of advice or an idea of what caught their attention are of course especially appreciated. I have lots to learn and each is a chance to learn something and a bit of encouragment.