I went from vertical ads to the 336x280 ads.
A few sites still had old square ad units but they were mostly inactive. Others I had to create new ad units.
Should I expect that it might take a few weeks for everything to smooth out?
There's been a definite drop in CTR and RPM since I did this a few days ago.
Google acts like the 336x280 is the best ad. And for my sites, it definitely fits better than the vertical ads.
But I have to admit, the vertical ads always seem to perform well.
I'm worried. I hope it's just a case of Adsense adjusting.