Blend and integrate. Period.

The more the AdSense looks like part of your site, the higher CTR you will get.

A very effective method I've used in a few web sites is making a link directory and placing a large 336 x 280 rectangle without borders and with the same background of your page on top of the links included on every category.

Of course it wouldn't work with the current structure of your new links directory. But maybe you can try the 468 x 60 banner instead, placed inside one of the links' divs on top of all the rest.

Hope the advice helps.

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