I have come to the conclusion that the more clicks a company pays for each month the cheaper their cost per click. So in Adsence terms my belief is Big Companies only give a few cents per click. I dont believe Google when they say they try and put the highest paying ads on your site so if you filter ads you get lower paying ads. If you have a site that has loads of ads for ebay, ask, exite etc. I bet the payouts per click is very low? Does anyones experiences match the above?
I remember some buy made sites and he had ads for ebay etc microsoft and ppc was high ... Big companys have big budgets ...
i totally agree with you filtering ad means you get low ads and thats what i have been experimenting few weeks ago