We all know you can only have THREE Adsense ads per page.
I've signed up with Lijit and I've placed three of their ads toward the bottom of my pages, so they're separate from Adsense and there is no conflict there.
However, Lijit has a "passback" code option where you can place Adsense code within the Lijit ad so that when a Lijit ad does not show, an Adsense ad WILL show.
Now, wouldn't this potentially result in SIX Adsense ads showing up on one page and be a huge violation of Adsense policy? Or would Adsense automatically cancel the requests for any ads beyond three ads?
I'm worried about using this option for these reasons, although it is tempting, since Lijit only shows ads about 50% for the time (for me). It would be nice to fill in that other 50%.