One of the first things we discussed on this blog was the importance of testing your ad copy. The slightest change to a headline or description field (changing a call to action from “Contact Us Now” to “Contact Us Today”, for example) could have a significant impact on your click-through and conversion rates. Clickable makes it easy to test your ads with our “Create Ad Variations” wizard, which we’ll discuss in another post. Today, I’d like to talk about another important component of split-testing your creatives: Ad Serving.

There are two ad serving options: “Optimize” and “Rotate.” If a campaign is set to “Optimize,” then AdWords will serve ads in that campaign on the basis of performance, giving priority to ads with higher click-through rates (CTRs) and Quality Scores. On the other hand, if a campaign is set to “Rotate,” the ads in that campaign will be served evenly. The default setting for AdWords campaigns is “Optimize,” but, to make your ad testing more “scientific,” you’ll want to change it to “Rotate.”

If your campaign is set to “Optimize,” your test will be skewed toward ads that perform well immediately, because those ads will be served more often. By changing the setting to “Rotate,” you’ll assure that you have a fair test: every ad will be served as often as every other, and their performance will be based exclusively on the ad copy, not on the frequency with which they appear.

Setting your campaigns to “Rotate” is simple. Go to the "Manage" section for your campaign, and click on the “Campaign Settings” tab at the bottom of the page.  The “Campaign Settings” tab is broken up into three sections: “Network Sections,” “Languages & Locations” and “Ad Scheduling & Serving.” Click on the link for “Ad Scheduling & Serving.” At the bottom of this section you’ll see the two “Ad Serving” options. Just be sure to select the radio button for “Rotate,” and click “SAVE!” at the lower-right. You’re ready to start testing.