I came across a good post with lots of tips from Jennifer Slegg of Jensense and Mr. Shoemoney himself.

Check out this cool tips

Jennifer Slegg

- Enable image ads on AdSense ads, use a secondary unit as an image only ad and you will get a lot of CPM ads, which is nice.
- Ensure the ad unit that has the highest CTR appears first in the HTML
- Sometimes labeling ads as ads on the site help, sometimes not
- Mix it up to prevent banner blindness (use ad rotation to use different styles and colors, use custom channels to test this stuff)
- To increase your CTR on forums, take advantage of Color Schemes rotation, change position and sizes and enable image ads.

Jeremy Schomaker

-Positives contextual ads, it is super easy to implement, they take out all the hassles of finding advertisers, dealing with them, etc. Negatives are that there is a "one click and gone effect." Only way to get paid is for them to leave. The user experience is not controlled by you, you do not directly control the ads that come up on those sites.

-Contextual Arbitrage:
What is it? If you buy from Microsoft to sell to YPN, that profit is the arbitrage. Why is it so profitable? Because the stats are right there for you, you know what your profit is right away.

Tools for Contextual Ads:
- Analytics is awesome (new vs. recurring visitors is a big stat)
- CrazyEgg.com has a cool to see where people click on your site

Tips for Success:
- Test
- Don't sell out
- Analytics
- Heatmaps
- Communication

More tips on seoroundtable