The share revenue idea was every where, sites contain their user's content sometimes share revenues, include Revver. But these normally apply to informative texts and multimedia files.

Webmaster-Talk, become one of the few to let the poster in forums share a piece of gold. The idea is great, it increase contribution rate of the user and make users feel that the posts can be worth a while to be posted.
Here is how it works:

Ad Revenue is shared between the Administrators, the new Thread Starter and the last replier in a particular thread.

As a new thread starter, there is a 50% chance your AdSense Code will be displayed for each page view. The last replier in a particular thread will have a 25% chance that their AdSense Code will be displayed for each page view and the administrators have the final 25% chance.

This should encourage both new thread posting in addition to participation in other member's threads.

Editor Comment:

I wish there is a time where all the forums in the world got a share revenue API on their page, at least I posted over 5000 posts in the world and that should generated at least 5 million page views for those sites.