Advertisers know that to be successful with google email list search ads, they need to be able to stand out in a competitive environment, which often means having ads qualified to show in coveted positions above search results. And since ppc is no longer a secret, there are always more advertisers ready to compete for those few highly desirable ad spaces. So when we learn that we can show our ads on new inventory when using a new google ads feature, such as responsive search ads (rsa), that grabs our attention. So where exactly does google get this new inventory that they claim could responsive search ads (rsa) be eligible? And what is the right way to evaluate the performance of this new inventory? We'll take a look. Ad testing should limit variables when we do a/b ad testing through our tools in optmyzr (my company), we strongly believe that we should be comparing apples to email list apples. In a perfect world, we would be able to replicate the exact same conditions for a search multiple times and display a different ad variation each time to get data on which ad is generating the best results, if that result is the best ctr, conversion rate, or conversions per impression (a combination of the 2 previous statistics). But we don't live in a perfect world, so we have to email list sacrifice some precision and try to keep the variables in our tests as low as possible. In google ads it is really very difficult, because many factors change and over which we cannot always control. In some cases, the best we can do is compare similar ad formats (eg, expanded text ads) within the same ad group where it targets the same audience. While it might look like an apples to apples comparison, it's often not because the ad group contains different keywords, which match even more different queries, and the ads are shown to people entirely different. In some cases, we'll be comparing different ad formats against each other, but that only makes sense if those ads were competing for the same ad space.