Bidvertiser is horrific waste of ad space.. There ads are so untargetted you wont get any clicks other then 1 or 2 accidental ones.. I earn 10 times more with adbrite as they actually know what they are doing and im not sure what other people are talking about.. I have 110% fill rate with adbrite.. Maybe helps if you get more then 10 hits per week.. Anyways best of luck for w/e you choose.. do like i did and try both for 2 days and whatever has the best results stick with it.