Moo.
I personally never found Top Cow comics that great. They have their runs where a writer will do an amazing job but most of the time, titles like Witchblade or Tomb Raider, seem very stereotypical. When I have the money to buy comics, I usually get independent comics, Vertigo, or a few good Marvel or DC comics (like the current main title Xmen runs)
And the OP should be “why are they popular”.
And the reason eludes me as well.
Witchblade, eh? If memory serves me correctly, the main character in that one is a rather scantily clad woman. Perhaps that has something to do with that particular comic’s popularity?
Reverse, you found the answer! The reason for Top Cow’s popularity is… BOOBS!!! Lots and lots of boobs!