A/B Testing From Search To Conversion

As I mentioned in a previous post, search marketers should work on finding the middle ground between a high CTR (appealing ads) and a high conversion rate (qualified traffic). This process is trickier than it seems because of the inverse relationship between those two metrics.

In this article, I’ll share a couple of thoughts which I hope you’ll find helpful when testing multiple ad copy and landing pages for your PPC program.

Get Your Campaign & Ad Group Ready

Once you have a fairly mature keyword list, you should be able to easily identify those top cost keywords with a Quality Score lower than 7/10. From my experience, 7/10 is definitely decent for non-branded keywords, while anything below 7 usually results in greater CPCs and greater first-page bid estimates.

By top cost keywords, I basically mean generic keywords – those guys where any slight Quality Score improvement can make a huge difference. You might want to isolate these keywords in specific ad groups so you can fine-tune specific ads and landing pages specifically for them – and you want to take care of this before getting the A/B test started.

This test might be a good opportunity to break down your top campaigns by device and/or geo so you can potentially look into device and/or geo specific data and come up with the best creatives not only for each top keyword, but also by device and/or location. This breakdown might be time-consuming and dilute the data; that’s why you might want to tier your campaigns.

Last, but not least, you want to make sure you’re using the “Rotate evenly” feature at the campaign level to give equal preference to all active ads in your ad groups. Keep in mind that “if ads in an ad group are unchanged for 90 days, the ad rotation in this ad group will automatically begin to optimize for either clicks or conversions” (see AdWords page).

Watch The Competition

As a numbers person, I wish I could come up with a formula to determine the best ad copy based on historical data and combinations of headlines, descriptions, display URLs and landing pages. The reality is that your search program success not only comes from your ability to draw conclusions looking at numbers, but also from your awareness of the competition.

More specifically, you should definitely search for your top keywords in Google and Bing on a regular basis, and see what the competition is doing in SEM and also SEO, then identify opportunities in terms of unique positioning: price, quality, free shipping, etc. You can use AdWords AdPreview tool to see “unbiased” search results.

Set Up New Ads & Landing Pages

This is definitely not a one-time thing, but rather, an on-going process with a 90-day limitation coming from AdWords.

1. Start with significantly different ad copy; each ad should boast a unique differentiator (price, quality, etc.)

2. Once you’ve determined the best axis of communication, fine-tune your headline without touching the description and display URL

3. Now that you’ve determined the best headline, test different descriptions

4. You can now focus on testing different display URLs

The scheme below represents this process in a simplified way:

Those tests will impact your CTR, Quality Score, rank, average CPC. They might impact your conversion rate, too. Ideally, you want your test to be as clean as possible, which means that you want to touch just one component at a time: headline, description, display URL, or landing page. This will help isolate every factor when determining what the champ ad is.

However, because of the relationship between CTR and conversion rate, you might want to test multiple ad copy and landing pages at the same time. You can rotate four ad copies per ad group with two unique ads and two unique landing pages so you can still get a good sense of the ad copy with the best CTR and conversion rate.

Top vs. Right-Hand Side Distribution

When testing multiple ads and landing pages, you definitely want to keep an eye on the distribution by “Segment: Top vs. Other” in AdWords, which simply indicates whether your ads are shown as the top of the search results, or on the right-hand side.
In the example below, we tested different strategies for one of our clients from a CTR to a conversion rate focus, until we found the balance between “good enough” CTR and strong conversion rate.

The bottom line is that a successful A/B test is a blend of “appealing enough” ad copies to secure a high Quality Score and top positions as a result, and a strong conversion rate. Search marketers should work on determining what is the lowest CTR to secure premium positions, then maximize the conversion rate while maintaining this minimum CTR level.