Seems that some people over at Threadwatch have noticed that if you have too many low-end websites in your Adsense account, actually lowers your payout. Tests HAVE been made. Full story at Threadwatch.
Seem that it lowers the payout for all the websites annexed to that particular account that contain those low-reputation websites.
Last year, Google let it be known that smart pricing is across your entire account and is not restricted to your under-performing sites. Read More: One poorly converting site can "smart price" an entire AdSense account [Jensense]
doesnt make an atom of difference, the high earning site isn't affected by the up and coming low end ctr sites.
No, actually your high earning site will be affected if you have a high enough amount of poor CTR sites.
To the extent this is true, it raises real questions about site development and the timing of the introduction of AdSense to new sites. If underperforming sites affect revenue on good sites in your portfolio, that suggests you should not put ads on those sites until you have built traffic and SERP. Google's probably sees it as a good strategy. By actively discouraging AdSense on under performing sites in people's portfolios, they are probably thinking it will reduce the number of sites with AdSense and help with ad blindness issues. Of course, none of this is relevant to people who are starting out with their first site.
wtf are they thinking. the goal for google is to maintain as many publishers as possible, but technologies like overall smartpricing for all sites will only force people to drop their sites with lesser earnings
No, I don't think that is their goal. Their goal is to have as many QUALITY (in their opinion) publishers as possible to ensure that advertisers get high quality placements and therefore high revenues. Google will then, therefore make more, too.
One month of data does not even come close to statistical significance here. A 15% and 3% change in revenues is nothing out of the ordinary. Do this for a year and I may be convinced something is going on.