I have been experimenting with link units for a while. First i decided not to use them because the pay out was so low, but now i think i found a good system that increases below the fold clicks on blog type website. In most blogs you can get a plugin for related post that place related post at the bottom of each post. use and vertical adsense link unit 468X15 Put it at the top and bottom of relate post "change the color to match your text". if someone comes looking for widget X, reads your post, didn't click a ad, then in the related post section sees a generic term for widget X, the chances or them clicking are high "very high" by doing this my number of Adsense clicks have increase by almost 30%. Now to be fair, link unit clicks are cheaper then in content click, but these are clicks i didn't have before. I'm averaging an extra $5-$8 a day on link unit click from those zones alone. Also to make more, sign up for textlinks and use the related tags link unit, just above the related post "i'm averaging $0.85 a day" Hope this trick helps you make some extra cash.