As with text and content, the banners need to fit visually into the context of the site design so colour schemes can be important – but for this you need very accomodating affiliate managers!
A visually sympathetic, on-topic banner is the ideal for any page. But they’re few and far between. No-one uses flashing or scrolling text any more, but a high percentage of banners still do.
Wish list: more static (or subtly changing) banners with understated colour schemes and game-specific imagery.
Bodog had it right when they introduced some stunning Blackjack and Slots creative towards the end of last year, but then they went and changed it for these black and white ‘personality’ banners that I just don’t understand.