AdWords currently offers three ad delivery methods – the ad rotation settings are illustrated here:
- Optimize For Clicks - AdWords automatically picks the ad that appears to be generating the most clicks
- Optimize For Conversions - AdWords automatically picks the ad that appears to be generating the most conversions
- Rotate Ads Evenly - AdWords will distribute your ad impressions equally among the ads in your Ad Group
Using the "rotate" setting for Ad Rotation is helpful for A/B testing  of ads – especially because the automated "optimize for clicks" and "optimize for conversions" ad delivery options have a tendency to declare a winner rather early, particularly for small and medium sized advertisers.
Ad Rotation to be Discontinued in AdWords
Starting next week, the "rotate" setting for ad rotation will be discontinued. Instead of rotating creatives equally, this setting will only rotate for a period of 30 days. After that, the setting will then revert to the "optimize for clicks" setting. Every time creative is enabled or edited, the ads in that ad group will rotate more evenly for a new period of 30 days.
As usual, Google claims that the change is to improve the system for both advertisers and users - in their words: "because the Ad Rotation when run indefinitely can inhibit advertiser performance and deliver less relevant ads to our users" and that "This change will enable us to provide users with the most relevant ad experience and should help advertisers improve the performance of their AdWords accounts."
(... Or maybe it has to do with increasing Google Revenues ?)
This change will forced on all AdWords advertisers  in the next week. At that time, ad groups with ads that haven't been added or modified in the past thirty days will be changed to the new ad rotation behavior. Otherwise, this change will begin 30 days after your last creative was enabled or edited.
Do you use the "Rotate" option for ad delivery in AdWords?
What do you think of Google's decision to (practically) eliminate Ad Rotation in AdWords? Do you agree with the way AdWords roll out these changes? Let me know in the comments fields below.
UPDATE: Ad Rotation Makes A Comeback
As of October 2012, Google has included the option the option to indefinitely rotate your ads. Apparently, fewer than 1% of all AdWords accounts had opted out of the ad rotation changes - this means that most advertisers still don't properly test their ads! To adjust your ad rotation settings, visit the "Settings" tab, within the "Advanced settings" section, lies a list of Ad rotation options: Optimize for clicks, optimize for conversions, rotate evenly, and rotate indefinitely! With all options to rotate your ads available, you no longer have to opt out of Google's Ad Rotation Changes!
Just because the option is back, doesn't mean you don't have to do anything! We'd like to remind our readers that the default setting will readjust your accounts to optimize for clicks. Make sure you change this!
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