On June 22, Google launched AdSense Labs, which gives publishers access to test newer features, which kicks off with two different Labs: Show fewer ads and Inline ads
With the Show fewer ads lab, the number of ads are lowered, to the point where users will see at least 10 percent ads. In turn, publishers, will expect to see a drop in revenue, but a drop Google estimates will be “negligible,” or less than one percent of revenue This is because the focus is to eliminate ads that will likely be deemed of lower value to a publisher’s visitors.
Inline ads are dynamically inserted mobile website ads sized 320×100. These ads will appear as users scroll down a page and don’t require programming for the publisher.
You can find Labs under the Optimization tab. Tests will be added to Labs as they become available.