Google AdSense Section Targeting
Google has introduced new features into their AdSense indexer (mediabot) which allow publishers to suggest to the bot sections of a web page to emphasize or de-emphasize.
To implement section targeting, you’ll need to add a set of special HTML comment tags to your code. These tags will mark the beginning and end of whichever section(s) you’d like to emphasize or de-emphasize for ad targeting.
<!-- google_ad_section_start -->
<!-- google_ad_section_end -->
To tell the bot to ignore an area of your page just add (weight=ignore) to the starting tag like so:
<!-- google_ad_section_start(weight=ignore) -->
You can use section targeting to make suggestions about as many sections of a page as you like. However, since the AdSense bot only visits your pages every few weeks, it may take some time before the changes take effect.
For WordPress users (or other Blogs), you will most likely want to add these HTML comments to your templates. For example, you’ll definitely want to emphasize the content of your posts and excerpts, but may potentially want to de-emphasize the sidebars, headers and footers.

