calico, the number of comments varies greatly. usually you get more by the more time you spend on deviant art. in the start I didn't get any comments, but as the quality of my pictures improved and as I got a larger network (by commenting and watching others who in turn watches me) I can get a decent number of comments, about 30 now if its a decent piece.
anyway, its a great place to use as a gallery even though its not a great place for critique.