Their update is pretty small – the changes in the heat maps from last time to this time are negligable (see below – the old version is on the left and the new one on the right).
Their main advice really isn’t anything particularly new but is a good reminder if you’re into forums. Here’s what they have to say:
Placement: Display your ad units where repeat users will notice them
• Because forum regulars tend to skip the header and go straight to the meat of the thread, placing your ad unit above or below the first post can be more effective than ads next to the logo.
• Place a leaderboard immediately after the last post. This provides users who make it to the end of a thread with a ‘next step’ when the content ends. Try to avoid placing it after the footer, though, as your readers will likely move to the next thread without seeing the ad.
Formats: Adapting your design for multiple ad units and limited space.
• Using multiple ad units, you can use a variety of formats to fill ad space throughout your site. Placing a skyscraper above the fold on the left side of your forum seems to produce slightly better performance than other positioning. However, when using multiple ad units throughout the page our horizontal bias still favors the leaderboard. Our heat map provides more details.
• Use horizontal link units, which are small enough to fit near the top of your forum just below the header. For the regular forum visitor, link units offer a wider range of relevant topics to browse.
In addition to the above they encourage opting into image ads which will bring more CPM ads into your forum (good because you’ll get paid for every view instead of just clicks which are hard to get with regular readers who become blind to the ads). They also encourage blending ads.
The other piece of advice I’d encourage is to mix your ads up. Rotate different color schemes through (AdSense allows you to include 4 per unit) and even consider rotating other ad network’s ads into the mix to really mix things up.
Found via Forumtrends (who add their own advice also).