Decreasing earnings and Conversion Optimizer

[Campo9]

I want to ask about if the lowering Adsense earnings can be possible related with the Adwords recently (april?) launched "Google Conversion Optimizer for Display network campaigns" where the advertisers set a cost per action (fill a form, send a mail, sell a product, etc) and then the CPC is calculated based on this.

My sites are receiving almost the same traffic (not hit by panda/penguin) but since a couple of months the Adsense earning decreased 40%.

[CoursesWeb]

Hi,
If there is approximately same number of click and visits, that changing in Adwords can be the cause.

[Chrispcritters]

Could also be smart-pricing

[netmeg]

I don't think there's one single thing you can point at and say "j'accuse!" but that could certainly be a factor.

[Campo9]

CoursesWeb:
Hi,
If there is approximately same number of click and visits, that changing in Adwords can be the cause.

No, same traffic but clicks and CTR are 30/40 % down.

netmeg
I don't think there's one single thing you can point at and say "j'accuse!" but that could certainly be a factor.

Exactly, I’m trying to understand what factors explain these changes so I can fix it.