This one got me, had to reply.
Now that Google secretly scores ads and landing pages, I would suspect you are paying more for adwords and receiving less for non-cents. You see they are charging more for what is perceived as non generating clicks that are not making them money. Non-clicks upset advertisers. Yep, people want something for their money they spend on adwords not just clicks.

For instance you have a high traffic blog and your users click on ads cause they like 'em or they want to support your, submit their email address or download a virus, for your effort you may get a quarter.

In this case you will get more than cents, but if you are a lowly blogger that same ad might pay you a nickel.

At the same time they are rewarding the fat spenders with high CTR scores with lower rates and placing them higher in the GSEP (google search engine pollution) rank.

It's time to not rely on Google for anything, you must have a Backup plan.
Since Google has dicouraged buying links, you really have no other choice but to buy advertising from them if that iws what you want, but if you use your imagination a little, do some reaserch and cross the tees and dot the eyes you can thrive without Google.

My advise to anyone with a mind, there are plenty of ways to make money online, Google just made it a whole lot tougher. Get rid of that googlesyndication.com paying pennies per click and make something that attracts people to you and your products and opinion.

It pays my bills. Bye Google, nice knowin' ya before you became evil.
Dann