Does having on same account sites with low paying niches (celebrities, games, wallpapers) together with some high paying sites (health, computers, etc) leads to smart pricing and less ppc on high paying sites? My friend says it does because smaller ecpm on low paying sites leads to smaller ecpm in general, which decreases the click value on high paying sites. What do you think? Any truth in that? Personal experience, maybe? Thanks a lot.
Yes, smart pricing works across your whole account and not individual sites. So, you better analyse your poor Ads and if possible remove them. Fortunately, smart pricing affect can go in a week's time or so.
Definately, the smart pricing will cause your CPC getting low when found the low pay keyword. CPC directly affect the eCPM since eCPM=CPC X 1000 X CTR.