They have banners. Not many, but they have em. Here they are in all their glory:
468x60s http://adv.slots.com/banner_search.php?casino=slots&category=7
12x90s http://adv.slots.com/banner_search.php?casino=slots&category=8
125×125 plus a bunch of other sizes (2 pages worth) http://adv.slots.com/banner_search.php?casino=slots&category=9
When they first started they DIDNT have banners. But they added them quite some time ago.