If it were not for adbrite, I might never had made it in affiliate marketing. If you can make it in adbrite, you can make it anywhere.
I think people need to keep a few things in mind. Their broad network PPC campaigns are pretty much worthless.
You can find individual sites that are an absolute bargain in terms of getting traffic and converting them, but it takes a lot of time and energy to sort the two out.
It has been a while since I delved in the Adbrite area, but they are on my list to go back, because I was able to make a pretty decent ROI there.
For someone new, it is not a bad way to get started as if you only do the site advertising, you have TOTAL control over your spend, you can spend very little (I think I started with $20 my first month), and learn the ropes. It is probably the most forgiving of any of the traffic sources I used in getting up and going in Affiliate marketing.
Probably also the reason why I never lost money promoting affiliate offers. I have been profitable from day 1. So it is not all bad, but it can be trying.