How it works is you decide which ad products to offer and what to charge for them. AdBrite serves your ads, bills your advertisers, and sends you a monthly check.
AdBrite specializes in flat-rate sponsored text-links (x dollars for y days) and cost-per-thousand-pageview (CPM) banners.
Even if you don't sell all your advertising text spaces you can choose to run Adbrite's network ads which you get paid for as well. Adbrite earn their money by taking 25% from sold ads on your site.
It's easy to place the ads on your site and if an idiot like me can do it I'm sure you'll have no problem!
I joined in May 2005 and in the first two months I've been impressed. Ok, it's not massive money yet but it sure beats Adsense and is a nice consolation to the depressingly low income yields from the various yet equally dreadful performing Amazons. To put it into perspective, I made more from Adbrite in one month than in a year of affiliate sales from amazon.com!
Adbrite works on the simple rule that the more traffic you get the more your income increases. Amazon works on the principle that whatever your traffic level your sales are going to remain alarmingly low. Well, that's my experience anyway.
Just give Adbrite a try. I'm sure you will be at least pleasantly surprised and at the end of the day what have you got to lose?