Google extends Drafts and Experiments to Display Network campaigns
The testing feature goes beyond search.
Campaign drafts and experiments in AdWords is now available for campaigns running on the Google Display Network.
You’ll now see the Drafts box next to the date range in the upper right corner when you’ve selected a display campaign. Clicking on that button brings up the dialogue box below showing the steps to get started.
Campaign drafts and experiments can be used to test changes to your campaigns, such as bid adjustments and strategies, without affecting performance. In drafts, you essentially make a mirror campaign in which to make changes. These can then be applied to the active campaign, deleted or executed as an experiment to test how the changes perform against the original campaign by designating a portion of the budget to the experiment for a period of time.