If you are running AdSense as a way to monetize your website, then you know how much you hate getting PSAs (Public Service Ads) showing on your pages … as they are non-ad generating.

What causes them? Usually the content of the page can’t be matched properly with an advertiser, therefore, a PSA is displayed. I’ve found this to occur even on pages with relevant content.

What can you do?

I’ve found a simple entry in the robots.txt file fixes the majority of the PSAs displaying on my AdSense pages.

User-agent: Mediapartners-Google
Disallow:

This code tell the Mediaparters bot from Google (the AdSense bot) they it has full access to your site (as noted by the Disallow nothing line).

I wrote an article on the basic of the robots.txt file and you can also look at my file over at Web Marketing Now.