The targeting type report displays how advertisers targeted ads on different web pages on your site. The data in the report is divided into the following targeting types:
After a site is crawled and indexed, AdSense will check the site’s content in order to find out exactly what the content is about. Then AdSense matches related ads to each webpage.
For example, a mobile review site with a lot of text content is more likely to get mobile phone related ads show up more frequently. The more text publishers have on their sites, the more easier it gets for Google AdSense to serve related ads.
Advertisers sometimes select a particular ad placements or particular ad units on a site, to run their ads in. The ads served in this targeting may not be related to the site content.
The other targeting type is to target specific users on your site based on their cookies and Google account. This will show what users are searching for and what is their interest.
For example, if a user searches for football boots and football. When this user lands on the publisher website they are most probably to see ads related to football from different football retailers.
Advertisers can also select no targeting or run of network: targeting all sites, except explicitly excluded sites.