In case you have been finding ways to increase your Google Adsense CPM and have not been successful then this tip might help you. Apart from position and texture of the advertisements, your earnings depend on what kind of content you have on your website and where the visitors are from.
Google Adsense bots are capable of reading your content and then providing with related advertisements to the visitor. In case you have user generated content being added on your website, you might notice that usually the content provided by your users like comments is of bit lower quality and they might use improper english.
This may affect the quality of advertisements that are shown on your website and to prevent such incidents from happening Adsense provides with a feature that allows you to define content of each page.
Users can use and on their website to help the adsense bot read your content and only show ads that are much relevant to your content. The tags need to be placed between the content you believe is related to the specific page. This can help increase your Click Through Rate on the website and hence your CPM.
Source : http://rudefox.com/increase-your-adsense-cpm/