Sitelink extensions, which are the ability to display up to 4 additional headlines and links within high quality/positioned AdWords ads (example below), were released by Google in November 2009 and since then have become extremely popular among Pay Per Click managers. This shouldn’t surprise anyone given the impact sitelink extensions have on increasing click through rate significantly in comparison to ads that don’t utilize this extension type.

Google AdWords Sitelinks

The following data gathered from 3 DragonSearch PPC clients ranging in industry display this significant impact on click through rate. Please note metrics marked as “SE” correspond to ads that displayed sitelink extensions while “No SE” corresponds to ads that didn’t display sitelinks. Also, it is important to keep in mind that these data sets were collected from 3 very diverse industries and thus have very different sitelink extensions ranging from promotions to whitepapers to contact forms.

Sitelinks Click Through Rate

As you can see from the right-most column displaying the difference in click through rates between ads utilizing sitelink extensions versus those that don’t, the impact of sitelink display is significant. This is nothing new as plenty of studies and fellow PPC’ers out there have given the same insight. The purpose of this post is to not answer how but rather why?

Why do sitelinks have such a tremendous impact on click through rate? Are the sitelinks that appealing or is it something else?

By segmenting each data set above by click type in the AdWords interface, the results are somewhat startling for ads displaying sitelink extensions as displayed below.

Sitelinks versus Headline

Looking at the above data sets, only about 6% to 7% of users who saw an ad displaying sitelink extensions actually clicked on one of those additional links with the overwhelming majority clicking on the headline of the ad.

Why Do Sitelinks Dramatically Increase Click Through Rate?

Since the same headline can display within ads that are displaying sitelinks and those that aren’t, the headline itself is likely not a factor in the overwhelming difference between headline and sitelink clicks displayed in the previous table. So why then do sitelinks have such a significant impact on click through rate if the sitelinks themselves are not the primary driver of clicks?

Ad Size

Ads utilizing sitelink extensions, especially those where 2 columns of links are used rather than a single line, take up more real estate than other ads. As a result, users are drawn to these ads simply because of their size. Of course relevancy between the ad and the user’s search query is still very important.

Trust and the Look of Being Official

Talking to several individuals on why they would select an ad utilizing sitelinks over one that doesn’t, nearly all of them mentioned a certain feeling of trust in the advertiser because of being presented with more options in the ad. In these cases, it was not the specific sitelinks that portray a feeling of trust and official authority but just their general presence. With the ever growing volume of spam and fraudulent activity online, trust can go a long way in attracting potential consumers.

Extra Effort Goes a Long Way

Although the implementation of sitelink extensions doesn’t take that long from a PPC manager’s perspective, the end-user is not aware of the simplicity behind this implementation. Therefore, ads using sitelinks tend to portray the advertiser going the extra mile in making his/her ad much more relevant and friendly to the consumer in comparison to other advertisers that seem to have just thrown an ad up and hope it works.

Your Thoughts?

Why do you think sitelinks have such a significant impact on click through rate? Have you found data that is similar or completely different from what I’ve detailed?

I’m very interested in hearing your thoughts on why sitelink extensions truly have an impact on click through rate.