Unfortunately, AdBrite does not automatically let you automatically display just banner ads on your site. You can display text ads alone or a combination of text and banner ads, but according to AdBrite, banner ads aren't available as a standalone option.

If you're like me and prefer banner ads instead of the lower-paying text ads, then utilize this tip that AdBrite recommended to me.

This does require you to turn off the "Auto-approve ads" feature, though. After you've done that, go to the section where you would review your ads and approve only the banner ads. It may take hours before the approved ads will appear on your site, and until you get a good pool of banner ads, you will see a few generic "Advertise here" placeholders.