Adsense can be a great way to monetize forums, but there are a couple “best practices†that I’ve discovered, and that you should test. 1. For all users, display a 728×90 adsense block just below the navbar. 2. For all users, try using a borderless 468×60 Adsense block at the bottom of the first post on each page of a thread. 3. For guests only, display a large adsense block beneath the first post. It’s also important to use Google’s section targeting tags around each post to place targeting emphasis on the post content. I’ve found that this approach maximizes Adsense revenue while minimizing user annoyance. And one extra tip: even though vBulletin and other forum software provides a page that shows recent posts, it’s best to display a box showing most recent or most active discussions on every page of the forum. This gives the site a much more active feel and ensures that posts in less frequented forums still receive attention.