Just a follow up question. What if you have a lot of different sites? Most of them are not doing very well. One of my blog has a high paying keyword. Google Keyword tool said it was 23 dollars. I manage to get a click to that blog and it gave me 30 cents.. Does it have to do with the content or the different sites of blog that I have that affected the per click?
This question gets asked over and over and over... and well over. Google does NOT disclose the formula they use to determine payout. The amount an advertiser pays for a click does not determine the amount you will get for delivering the click to the Advertiser. One site may make 5 cents and another 5 dollars for the same ad. On the same site you may get 5 cents and 5 dollars for the same ad at different times of the day. You can read the Adsense TOS for yourself. Site penalties are usually applied per account not per site according to information obtained by Jennifer Slegg http://www.jensense.com/ If you are going to be gullible you may as well look for more definitive sources from people that at least appear to have a basis for what they are talking about.
There is no sure fire way of knowing this, but based on advertising industry estimates on similar businesses cut i s usually around 30%. Obviously noone knows 100%