Is it OK to rotate Yahoo and AdSense ads?
Yes. They just can’t show up at the same time. It used to be a bad idea to do this. Lisa from support found that on one site, the Yahoo bot that crawls pages to determine the content was getting confused because the page content was constantly changing and the Yahoo ads were there one second and gone the next. So each time a Yahoo ad was displayed it triggered a new “content review” and PSAs would be displayed. Now it’s been fixed.