I made like 5 bucks the first day using bidvertiser then they cut me off, I earned NOTHING after that. It's a terrible program, you can't earn with it.
I'm always surprised what my visitors will buy and what they won't. Same with Clickbank. I didn't think they would be interested, but wow, the money just keeps rolling in. Same with CJ. The obvious products they should be buying, they don't. Then I throw in a completely weird product, and it sells like hotcakes.
I used clickbank on my search engine generated 3 sales totalling $98 in commission which were refunded to the buyers so i made $nil.
Have you thought about rotating bidvertiser and adbrite using your own ad rotating script? That way the variety that each unique is serverd doubles. I'm not sure how many people have had success with this though.
I know chikita is very very picky. They rejected me and said they only accept sites that are a sure cash cow.