The Importance of SEM Ad Copy Testing: Lessons from a Simple Brand Test

The Importance of SEM Ad Copy Testing: Lessons from a Simple Brand Test
Wednesday, April 09, 2014
Charlene Veras
SEM

Writing compelling ad copy in search engine marketing (SEM) can be one of the most important things we do. It plays a critical role in increasing your ad rank, boosting click through rates (CTR) and, most importantly, improving conversions. The desired outcome of an ad copy test is to determine what type of message delivers the highest CTR, lowest cost per click (CPC), and ultimately what drives the most efficient cost per conversion. There are a number of elements that should be under your microscope when testing ad copy; some are CTR, ROI (return on investment), quality score, cost-per action (CPA), conversion volume, total clicks and average position.

testing2 After performing an ad copy test across a series of brand campaigns in one of our larger      accounts for one month, we found that a seemingly insignificant change like including the  client’s brand followed by “Official Site” in the headline led to significantly better results to the tune of a 10% increase in CTR and traffic; a 12% increase in conversions; and a 22% lower CPC throughout all brand campaigns. Looking back, it shouldn’t be surprising that the experiment ad with the official site messaging outperformed the control, which only included the brand name in the headline, but had we not tested, we never would have realized these meaningful performance gains.

In addition, when users’ search queries contain the brand, the user is most likely to be brand loyal and generally further down the conversion funnel. Therefore, including “Official Site” in the headline, emphasizes site credibility and entices the user to click on the ad. Since the results of this test proved to dramatically increase brand performance, it brings to mind other testing ideas, like trying “official site” messaging against the brand followed by a registered trade mark symbol.

How to Track Your Ad Copy Test

When performing an ad copy test, it is important that you know exactly what you are going to test, to determine how long you plan on running the test and to have an effective way of tracking and reporting the results.  If you’re not organized when performing an ad copy test, then the chances of sabotaging or invalidating the test are very likely. Here is a checklist that all search engine marketers should adhere to before launching an ad copy test:

Campaign Settings – Set ads to rotate evenly

Length of Test – Run for at least two weeks (depending on campaign volume)

Tracking Performance – Document conversions, CPA, CTR, CPC, clicks & position prior to launching test

Determining the Winning Ad Copy – The ad with the highest CTR, lowest CPC & most efficient CPA

Choosing the Winning Ad copy:

When it comes to determining the winning ad copy, it is important to use a statistically significant tool in order to determine that the result was not due to coincidence or chance. A test is statistically significant when there is an even and large set of data (impression volume) and the confidence level (expressed in %) of the winning ad copy will fall between a set of values. Statistical significance tools already provide us with the set of values, which simplifies the process of determining the winning ad copy. After the test runs for at least two weeks, you can determine if the test is statistically significant by using any of the statistically significant tools listed below:

http://getdatadriven.com/ab-significance-test

http://www.pointit.com/ad-copy-testing-for-statistical-significanc/

http://visualwebsiteoptimizer.com/ab-split-significance-calculator/

Now Go Forth and Test

Testing ad copy in PPC is essential in order to increase overall account performance. While monitoring this test, we made sure that our campaign settings were set to rotate evenly, we allowed the test to run for at least two weeks (in order to ensure that the test would be statistically significant), and we focused on the main metrics such as conversion volume, CPA, CTR, clicks and average position. It can be hard to carve out time to do ad copy testing with everything else that goes into making your campaigns successful. But, as this specific example demonstrates, seemingly small tests can pay off big time. As search engine marketers, ad copy testing is something we can’t afford not to do.