Adbrite

AdBrite, "The Internet's Ad Marketplace", is an e-commerce site. Rather than selling books, CDs, or rare antiques, AdBrite sells ad space on thousands of websites.
If you're a publisher, use AdBrite to set your own ad rates, and approve or reject every ad that's purchased for your site. AdBrite enables you to instantly sell ads to your visitors via a "Your Ad Here" link, in addition to selling through AdBrite's marketplace and sales team.
Our revenue split is 75/25 in your favor. Through a small snippet of HTML placed on your site, we handle serving, scheduling, billing, customer service, and sales. About half of AdBrite's sales are generated from our marketplace and sales team, while the other half are generated from users clicking "Your Ad Here" on our publisher's sites.
While AdBrite can provide publishers with more revenue and better ads than traditional ad networks such as Google AdSense, we work fine along-side them as a simple way to generate additional ad revenue by selling ads directly to your visitors -- something the other ad systems don't do.
If you're using AdBrite in addition to another ad network, you can turn off AdBrite's "run-of-network ads" and AdBrite will only display ads that have been approved by you. If you have no ads running, AdBrite will display nothing but "Your Ad Here", so no real estate is wasted and you have nothing to lose.
AdBrite doesn't display the big "brick" of ads that you're used to. Rather, AdBrite gives publishers full control over the look and feel of their ads so AdBrite can be integrated seamlessly into any website.