Don't know if this has been discussed before but I thought I'd throw it out there.
Just redeveloped an old HTML site and transfered the content into Wordpress. Running 3 ad blocks on the pages - square block in sidebar, another in footer and small banner after post content.
Ads are displaying fine on all pages except 1 new page. The page is entirely content I copied from an old forum post (I'm removing the old forum as part of the redevelopment and want to convert the popular threads into blog posts). Could this be some kind of anti-scraper measure?
All other old pages (pre-existing HTML content) display ads fine and new posts I've added after the copied page are displaying ads fine. Just this one page that just displays white boxes where the ads should be.
I had all 3 ad blocks setup to display only text ads. I changed the footer one to also show images earlier and it's now showing an image ad, but over the past 3 or 4 days the page has never shown text ads.
Sadly I have no experience with this type of thing, but believe me I am following this post closely as I've been wondering about G being able to do this type of thing on a large level. I don't really think they could do that without causing massive issues across the board, but who knows anymore.