Google has announced in its AdWords blog that the ACE tool is going to be rolled out to all advertisers, starting in the US from this month. ACE - or AdWords Campaign Experiments - is a free tool within AdWords that makes it easier to test and measure the impact of changes to different campaign elements, including keywords, bids, adgroups and placements.

This new feature was first announced in a beta versions several months ago and is a significant enhancement for advertisers to test and review potential campaign improvements. Google says that advertisers in the beta test period have reported that ACE has helped them feel more confident in the impact of their campaign changes, making it easier and less risky to try different strategies and optimize more frequently.

Experimental changes to a campaign can now be run side-by-side using ACE, with the original campaign in a simultaneous split test. This approach lets advertisers run shorter tests that start and stop whenever they want, with less concern about results being affected by seasonality or other factors. Google says that advertisers will get more precise impact estimates and more chances throughout the year to test and improve performance.

The new ACE tool will appear under Campaign Settings for US advertisers initially and is still showing as a beta test, but this will hopefully be rolled out globally very soon and become a valuable part of an AdWords toolset.