When you visit new AdSense Interface, you will find Performance reports tab, you’d likely stumbled upon the Columns button. This button lets you customize your report to view “earnings by page views, ad requests, matched requests and individual ad impressions”. Selecting one of these options will change the columns and data shown in the table and graph. All other metrics, like CTR & RPM, will be based on the selection you choose.
“To get an overall sense of your ad performance, view your earnings by “page views”. When looking at specific ad units or channels, however, we recommend using the “ad requests” view. This’ll provide you the most accurate numbers for specific reports like ad units, ad sizes, custom channels, ad types, targeting types, and bid types,” suggests google.
Why’s this? “When analyzing the performance of individual ad units, the “page views” view may show you inaccurate CTRs and RPMs if you’ve multiple ad units on one page. Each time a user views a page with multiple ad units, your reports will log only one page view and associate it with the first ad unit on the page. This means that when you’re viewing more granular reports by “page views”, the CTR and RPM of the second and third ad units on the page will be calculated based on “zero” page views, resulting in invalid data. By using the “ad request” view when looking at specific ad units, you’ll ensure that you’re reviewing valid CTR and RPM values,” explains Google.
Try it now! Navigate to the new interface and click on the Performance reports tab, then select the “Columns” button from any report to change the metrics you’re viewing.
[Source: Inside AdSense]