We’re excited to announce that AdWords Campaign Experiments (ACE) is rolling out to all U.S. advertisers. ACE is a free tool that makes it easier to test and precisely measure the impact of changes to your keywords, bids, ad groups and placements. Over the last two months, advertisers in our beta 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.