Google Adsense rollout this week more experiment types and “a better understanding of how they impact earnings and users with some new updates.”
With the new experiment, Adsense publishers are now able to “know how the settings you experiment with impact your user experience.” Publishers “can now see how long users spend on your site with a new “Ad session length” metric that has been added to the Experiments results page.”
Here an example:
What is Ad session length?
“Ad session length measures change in ad queries per session. If the variation has longer sessions, it’s a good sign that users spend more time on your site and may have a better experience. In the case of neutral metrics, the impact is negligible and it’s recommended that you look at other metrics to choose the winning experiment setting.”