Display ad builders are generally pretty bad, imho. I've used pretty much every one under the sun and I think you're better served by using something like 99des

Display ad builders are generally pretty bad, imho. I've used pretty much every one under the sun and I think you're better served by using something like 99designs to get banners made. Generally, you'll get a better overall banner from something like that. However, the Yahoo display network banner builder does have one great thing: it shows the CTR for an ad template. That can help identify templates that are winners, but take that number with a grain of salt as well.