"Only the tits get the hits" has long been the rule of the Rosity galleries. Some people who do fractals and the like have even gone so far as to make sexy pinup thumbnails for their abstract images. That does increase their hits to insane levels, but it's hard to tell how many of them are due to the sexy thumbnail, and how many are due to people clicking two or three times, wondering why the thumb doesn't match the image. ;-)