realmaverick - 6:51 pm on Oct 11, 2012 (gmt 0)
Here's a useful quote from the Google blog article:
If you decide to update your page layout, the page layout algorithm will automatically reflect the changes as we re-crawl and process enough pages from your site to assess the changes. How long that takes will depend on several factors, including the number of pages on your site and how efficiently Googlebot can crawl the content. On a typical website, it can take several weeks for Googlebot to crawl and process enough pages to reflect layout changes on the site.
Funnily enough, that piece of information was released alongside the ATF launch in January. However, despite tearing my pages apart and trying many many different designs, nothing had any effect.
But the update on the 9th, has had a big positive impact.
I think Matt's probably being honest, in that changing your layout can resolve the issue but I also think for many of us, we were fighting a losing battle, as the algo was taking more in to account, than just ads above the fold.
An educated guess would be, low textual content even a single advert, would trigger this in some cases. Perhaps also, their ad detection methods have gotten better in this most recent update.