Google’s Product Listing Ad format has grown impressively over the past 4-5 years, and in Q4 clicks on these image-based ads were up 62% Y/Y. Much of this growth was driven by traffic coming from mobile devices, with phone clicks up 180% Y/Y for Q4.
While increased mobile usage, a larger PLA format, and the growing presence of PLAs on large retailer search partners all played a role in driving up PLA traffic coming from phones, another interesting wrinkle began to impact mobile growth in December: Google began showing PLAs in image searches on phones for advertisers with PLA campaigns opted into the search partner network.
As you can see, the PLA carousel is featured above the image results for the search [nike running shoes].
Selecting a color filter refines both the images and the products featured in the carousel to just the color(s) selected.
Impact on PLAs
As image searchers are more likely to be seeking a simple image of a product as opposed to trying to purchase a product, conversion rate for this traffic is likely lower than that of PLA traffic from Google.com searches.
However, it’s impossible to measure exactly how different conversion rate for image search traffic is vs Google.com traffic as image search performance is lumped in with other search partners.
In aggregate, search partner PLA traffic conversion rates were 48% lower than Google.com PLA traffic in Q4.
We’ll be watching how that figure changes in the coming months, though any trends observed may just as easily be caused by other search partners beginning or ending agreements to feature PLAs.
Fortunately for advertisers, cost-per-click of search partner PLA phone traffic has been decreasing relative to Google.com traffic since mid-2015, and was 51% lower in December.
Thus, the price paid for search partner PLA traffic on phones relative to Google.com traffic is roughly equal to the value of partner traffic relative to Google.com.
Advertisers are able to target just Google.com with PLA campaigns, but cannot adjust bids for search partner traffic vs Google.com traffic for campaigns targeting both, and campaigns cannot be targeted to just the search partner network. This means advertisers are at the mercy of the auction in terms of search partner return on ad spend matching that of Google.com.
Between image search and retailer search partners, search partner traffic is becoming a bigger part of PLA spend every day. As such, advertisers looking to take full advantage of the PLA format that aren’t targeting the search partner network with their campaigns may want to reconsider, particularly since the cost of this traffic seems to be lining up well with the value relative to Google.com so far.