How to improve your Adsense performance in one step

Improving your Adsense through concessions

You'll need to disregard your holdups about slightly invasive placements because to see any real return on your Adsense you'll need to put this unit in the way of the content and make it blend.

adsense unit Intentional vs Accidental clicks
Ideally you want the unit to be clearly an advert but blend well enough that you'll still get a few accidental clicks, because if you uberblend it then your readers will see you as a money hungry troll and disregard anything you have to say. If you make it stick out like a saw thumb then you'll get next to no clicks. It's a hard trade off and I've found (thus far) that matching the link colour is sufficient to bring in some extra money.

Blending
Google's Terms and Conditions indicate that you can't mislead your users into clicking the unit by making it "appear" like it's part of your site. For example putting it within your "related articles" list and styling it so that users couldn't tell where your content stops and the advert starts is definately not on.

How much can you expect to see

Google would be slightly "miffed" if I detailed my earnings but I can give you a general idea of what to expect from a unit. My unit performs reasonably well, accounting for 70% of all Adsense earnings - above the bottom unit.

Why this placement combination works
Having the unit embedded in content at the top means that it's in a focal position if users have read the first few lines and are going to navigate away, but it also collects those users who are a tad clumsy with their mouse. The bottom unit is for those who have read the article (or skimmed over it) and are then deciding their next action. They can either continue on to the comments or navigate away.

Avoid over-invasiveness
I dislike sites where the ads are utterly unavoidable and break up the article. I figure that having an adsense unit in the middle of the content - say, half way down - would perform rather well but completely ruin the flow of the article. With the embedded unit you are still able to ignore it because it's not in a primary position.

Conclusion
Nothing clever about keyword use or anything, just the manipulation of a simple formula. More clicks = more money. To get more clicks you need better placement and the square unit embedded in content seems to be the best performer possible. So if you're serious about seeing some return for your blogging efforts then this is your best option. If you're a purist then it's best avoided because I can concede that it is slightly invasive but that's the only real way to make money through contextual advertising mediums such as Google Adsense.