epc,ctr question

difference between ads

[alezimolo]

Is there any differences for the EPC/CTR and impressions between an ads with for exemple 2 adsand another with 4 ads?

I had pages with skyscraper with 4 ads where the epc was very low and replace those ads units with ones with 2 ads, does it make any difference for the calculation of both CTR/EPC and the number of impressions counted?

Or do Google only count by number of block units?

[arrowman]

Google counts the number of ad blocks that are displayed.

You may get different ads and clickthrough behaviour though.