If you, a blog or website, provide your content to another website, and that other website re-brands it and serves ads alongside it, what percentage of the ad revenue should the other website share with you?

You might want to check out this site becasue you can download their contract and review the terms.

As for actual compensation, there would be a number of factors:
-What percent of the content on their site is yours?
-What kind of traffic is the site getting?
-What percent of his site revenue is based on the ads?
-What is the value that your content adds?
-Will your content increase their traffic?
-What effort are they bringing to the table, are they just setting up and RSS feed and adding the Ad server code?
-Who will benefit more from the agreement? (i.e. are you gaining exposure or are they gaining your audience?)

Not sure about case studies, I’ll see if I can find any.

It would depend on your agreement with them that gave them permission to do the re-branding and to reproduce your content. It could even be nothing (let us hope you did not do that).

Zero – my content is always licensed under a Creative Commons-Attribution-Sharealike license (see Creative Commons). I consider it an honour for my content just to be spread around. (Heck, my latest blog article was translated in another language – that is very satisfying :).

Sharing ftw :)