So, we are always on the lookout for ways to squeeze a bit more meaning into a search ad. One component of the ad which is usually overlooked is the landing page subdomain.

Although the landing page subdomain is invisible in many types of advertising, it WILL normally be visible in a search ad – Google shows the landing page subdomain as part of the ad copy. And it will often also be visible in the user’s browser after they have clicked.

It’s a subtle feature, and many users will not notice it, but some will. Choosing an appropriate subdomain helps to build user confidence and will increase conversions. Conversely, choosing a subdomain that is confusing or distracting will undermine user trust and harm conversions.

A Subdomain Case Study

Recently we set up a new subdomain for one of our clients, YPO, the UK’s largest public sector buying organisation, in order to test a new set of marketing landing pages.

For technical and analytical reasons which I won’t go into in this post, setting up a new subdomain was the best way to ensure we could get good, clean results from our test.

The test itself was unrelated to the search ads in anyway so the only difference that users could see in the ads was the display URLs—and the only difference in the display URLs was the subdomains.

In this case our original subdomain was the generic ‘info’ and the new domain for the test was ‘catalogue’ – which we chose as an alternative simply because receiving a free YPO catalogue was the call to action for the campaign.

The test campaign, however, resulted in an unintended but extremely interesting outcome: changing the subdomain for the lead generation campaign resulted in a significant increase in the click through rate from our paid search campaigns.

And by significant, we mean very significant. The new subdomain had a 51% higher relative CTR on a like-for-like basis.

Now I would love to say we intended to achieve this impressive conversion improvement—but actually we were testing something entirely different at the time.

However, we’re now reviewing our use of subdomains across campaigns and looking at them not simply as part of the technical set up, but as a conversion optimisation opportunity.

Maybe you should too?