Help Google AdSense distinguish what content is relevant on your website.
Most often Google AdSense place ads on your site that are relevant to your content but sometimes Google gets it wrong. It can also be times where you don't want Google to put any relevance to a certain text on your site when they crawl it.
An example would be if you write a blog post about that you don't like poker sites. Then it would be unfortunately if Google showed ads for poker sites on your blog.
With Relevant AdSense Ads there is now an easy way of helping Google distinguish which content that you think is relevant and which content should be ignored.
Remember though that this is only suggestions to Google AdSense and they might ignore it completely. It could also take a while before it take effect on old blog posts because Google must of course crawl it again.
For more information, see Google AdSense help page about section tageting.
Follow the development of this plugin at FredrikMalmgren.com.