If you are a user of Google's AdWords service, then you are probably familiar with the Ad Rotation feature. The Ad Rotation feature currently offers three settings - "optimize for clicks," "optimize for conversion," and "rotate evenly." Google figures that they can fix up these settings so that the most relevant ads are always delivered to the user.
To that end, Google announced some changes coming to Ad Rotation next week. The company hopes that the change will "provide users with the most relevant ad experience" and "help advertisers improve the performance of their AdWords accounts."
So what does this new update entail? The "rotate" setting is going to change. Normally, creatives rotate for an indefinite period of time. With the new update, this setting will only rotate for a period of 30 days. After this period of rotation, the setting will then pick the ads that are expected to generate the most clicks. It's also worth pointing out that whenever a creative is enabled or edited, the ads in that particular group will "rotate more evenly for a new period of 30 days."
While you already know that this change will be coming next week, it's important to note how it will affect current ad groups. If you have created an ad group with creatives that haven't been added or modified in the past 30 days, the new ad rotation will be applied automatically. If you have altered the ad group, the change will come about 30 after the last activation or change.
Like with any new change, it may confuse some users. If you have any questions, consult Google's documentation on the changes. It provides all the answers you need in regards to the changes coming to Ad Rotation.