Assessing the Impact of Image Extensions

By Matt Umbro | @Matt_Umbro | Senior Account Manager, Community

Google first announced image extensions in beta in June 2013, providing an exciting opportunity for advertisers to include visual content directly in text ads. Playing off Product Listing Ads (PLAs), which have produced great click-thru and conversion rates for many advertisers, image extensions allow for three visuals to show at the top of text ads. These ads not only look more visually appealing, but also occupy additional search real estate. Here is an example of an image extension.

Example of Image Extension

I was initial excited about image extensions because of their ability to visualize concepts. With this extension, companies not using PLAs can still use visuals. The example above uses images of a hotel and of the Sydney cityscape. These images grab the eye, helping the ad stand out even more than what other ad extensions can achieve.

I first heard about the beta in April 2013, and was able to get one of my sporting goods clients in the door. This client was running PLAs, however, so we used the image extensions for concept related terms (ie: terms around training and specific skills).

Before going live, the advertisements must meet a few requirements. First, the images need to be associated with specific ad groups. Based upon five popular ad groups I asked my client to provide three images for each group, fifteen in total. Images must be representative of all keywords and ads in the particular ad group. In other words, you can’t use an image of someone drinking coffee for an ad promoting running shoes. Second, image extensions will only show if your ad is in position number one above the organic rankings.

Reviewing the Data

Fast forward one year and I’m ready to present the data, organized by click type, consisting of:

  • Headline Clicks
  • Image Ad Clicks (Image Extensions)
  • Mobile Clicks-To-Call
  • Product Plusbox Offer Clicks (now retired)
  • Sitelink Clicks

Note that these clicks are solely on Search Network text ads. Display and PLA campaign data are not included.

In reviewing this case study there are a few other considerations to keep in mind.

Small Sample Size – This extension only had the opportunity to show in five ad groups. Remember that this extension only shows when text ads are in the top position.

Images – The images used in this extension remained the same throughout the year. Though normal optimizations were made (keyword bids, negative keywords, etc), the images were not touched.

One Client – This data only represents one account in one vertical. Since I was only able to get one client on the beta I have a limited sample. The data may look different when analyzing multiple accounts.

The table below showcases click and impression data by click type.

Table of click and impression data

It’s no surprise that headline clicks are the most abundant. Even with the additional real estate that extensions occupy, the headline text is larger, which generally makes it more eye catching and easy to click. I am surprised that image ad clicks accounted for a lower CTR than headline clicks. Because they occupy roughly half the ad, I believed more searchers would click an image based upon the same principle as the headline.

When reviewing the average cost per clicks, image ads are the highest. Again, this doesn’t come as a surprise; image extensions need to be in position one to show. It does beg the question of how conversion and revenue metrics are impacted with such a high CPC. Speaking of which, here are the conversion and revenue metrics.

Table of Image Extensions conversion data

First off, I am disappointed to see that image extensions only accounted for 11 conversions during the year. That’s less than one conversion a month! Even though conversion rate and average order value are higher than headline and sitelink clicks, the sample size is relatively small. Additionally, cost per conversion is higher, as our CPCs are that much more expensive than other click types.

The final table looks at each click types’ percentage of overall metrics.

Table of percentage of Image Extensions data

Image ad clicks only accounted for 0.18% of total clicks and 0.20% of total impressions. This data highlights the scarcity of how often the image extensions were presented.

Final Thoughts

Image extensions are a great idea in theory, but put to the test they had minimal impact. They gained so little exposure that it was tough to get a statistically significant sample size. Even when they did show, the metrics were okay, but generally did not perform as well as other click types. I still like the idea and would run this feature for other clients, but I don’t expect the needle to significantly move.

What have your experiences been with image extensions? Please leave your comments below!