I have a few pages on my site that are very popular. My thought is that I could encourage other sites to link to a dynamic version of those pages, which contain Adsense ads, by offering to share revenue, much as DigitalPoint does. I could give them a url that allows them to plug in their Adsense user ID and channel ID, which would modify the ads on the page when called using that URL. I could have another ad block that contains my own ads -- or not, hoping that the increased traffic and backlinks improves things overall. So my question is: Is it legal with Google to place two ad blocks on a page, each with different user IDs and channel IDs?
I don't see why not. I see nothing in the TOS against this. However, I would run it by google just in case. It can't hurt too.
I think you could without your ads too in a same time. Only one publishers code is allowed on single page.
It's a ToS violation to post two or more Ad units with differing publisher ID's. Only one publisher ID may be used per page.