Of course the point is not to "double up" accurately "to increase" revenue, just in my case, after understanding some of the principles of AdSense, revenue is doubled, I put here the results for luring.
So, how to increase CTR and CPC, and thus the RPM, and therefore AdSense revenue, and (for the kids) what do these buzzwords?
CTR - the percentage of visitors who clicked on the ad (conversion). To increase the CTR, ad units do more, brighter, put in the right places, properly fit into the design.
CPC - average cost per click on your ad. To increase the CPC, use those ad formats on which the greatest demand among advertisers, and thus the competition and, therefore, cost per click, but keep in mind that in different countries different popular formats (say the most popular car body in Russia is a sedan, and the ad format is square). Do not forget to allow both text and media announcements, then the system will be able to choose the format with the highest price of your click.
If you do not know the basic tips that everyone should know the AdSense Publisher sure to read them. They are best in my opinion are collected in a recently published booklet in honor of the 10th anniversary of AdSense.
And most important - experiment! After the experiment, do not make hasty conclusions, wait at least a week, and preferably two, before you determine for yourself the result of the experiment.
And do not limit yourself to the generally accepted advice, only you know what is best for your project and your users.