It is easy to implement section targeting, you only need to add HTML comment tags to your code. These tags will mark the beginning and end of whichever section(s) you'd like to emphasize.

The HTML tags to emphasize a page section take the following format:

<!-- google_ad_section_start -->

<!-- google_ad_section_end -->

 

You can also designate sections you'd like to have de-emphasize for ad targeting.to the starting tag:

<!-- google_ad_section_start(weight=ignore) -->

 

One of the major advantage is, this feature will help those publishers have much more relevant ads. Navigation menus tend to screw ads, meaning Adsense crawler will have problems with displaying ads that are focused on one aspect of the navigation menu , rather than ads targeted specifically to the content of the page.
 

Adsense crawler indexes the pages only once per month and hence.In order to properly implement this feature, you'll need to include a significant amount of time and content within the section targeting tags. Including insufficient content may result in less relevant ads or PSAs.