Desktop vs. mobile search results in e-commerce
In this 3rd post of the e-commerce search results series, I compare mobile with desktop SERP Features and SERP layouts.
In the last two Growth Memo episodes, I shared my findings from dissecting 20,000 ecommerce keywords.
It started with looking at the desktop search results and observing that most SERPs don’t show 10 results anymore.
In the second part, I analyzed SERP Features in e-commerce, concluding that the SERPs become more visual, localized, and crowded with ads.
To conclude this series, I want to compare the findings with mobile SERP Features. Desktop and mobile search results are not the same. Both devices are used in different circumstances and come with different use cases. Why should the search results be equal?
# first-page results
To be precise, when we talk about “the first page” for mobile search results, we’re talking about the search results until Google shows the “load more” button.
In 2018, Google introduced the “load more button” for mobile devices, which now rarely appears for users. SERP crawlers, however, still see the “load more” button and can emulate what a “first page” on mobile looks like. 
The first trend the data shows is that 63.4% of mobile search pages still show 10 results - almost 2x compared to desktop. While the number of results showing 5, 6, or 7 results is almost equal between desktop and mobile, they start to diverge for longer SERPs. Almost 3x as many search results have 8 results on desktop compared to mobile.
My assumption is that Google shows more results because users are used to scrolling on mobile devices. Scrolling and swiping are native ways to use smartphones.
Top ads and PLAs
As mentioned in the previous post, the one way to make sure you show up at the top of the search results is by paying for it. Not every search result has ads, but it’s important to understand when and how they show up if you want to combine ads with organic results or understand the impact of ads on organic traffic.
Two types of ads matter in ecommerce SEO: top ads and PLAs (product-listing ads). On desktop, 64.1% of keywords show top ads and only 17.8% show PLAs.
On mobile, 36.1% show top ads and 29% PLAs.
In plain terms, mobile results are almost twice as likely to show PLAs compared to desktop, while top ads are almost twice more likely to appear on desktop.
When they appear, 28.5% of desktop top ads on desktop are four-packs (example below), while single or double packs are more likely on mobile.
Pages with 10 results show a lot more top ads on mobile than pages with 9, 8 or even 7 results. The curve is steep.
Why is that?
Because more mobile search results show 10 results (meaning 10 results until the “load more” button). The same pattern emerges for PLAs: SERPs with 10 results show more PLAs on mobile because there are more 10-results pages on mobile devices.
On desktop devices, top ads and PLAs show up mostly for pages with 9 or 10 results. They occur more often than mobile PLAs, except when it comes to 10-results SERPs. Mobile searches with 10 results feature top ads 39.8% but PLAs 73.7% of the time. On desktop, Google shows top ads for 70.8% and PLAs for 86.8% of 10-results SERPs. A big difference.
What can we take away from all of this?
The more search results Google shows, the more ads we see. That seems to be especially the case for SERPs with less than 9 search results, presumably because the intent is more ambiguous. The takeaway is that the most powerful way to drive traffic is through the most powerful way to drive traffic is a combination of both organic and paid results.
Map Packs play a special role on mobile devices since smartphones were literally invented to be portable. As such, you would think mobile SERPs are inherently more prone to mobile results, but Google shows roughly the same amount of Map Packs on mobile as on desktop: 69.7% of mobile results show Map Packs while it’s 77.7% on desktop.
For pages with 10 results, Google shows Map Packs for 71% of mobile and 75% of desktop results.
As stated in the previous analysis of desktop SERP Features, if you’re a retailer with locations being present in Map Packs is key. If you’re not, you need to understand their impact on organic traffic (spoiler: it’s not great). Ideally, measure CTR and traffic when Map Packs are present for important keywords and compare it with keywords that don’t show Map Packs and where you rank in the same position.
Image carousels present companies with unique opportunities to crack competitive SERPs when classic organic ranks are hard to move. However, the data shows something else.
63.5% of desktop search results show an Image Carousel but only 23.7% of mobile results.
My assumption is that Google shows popular products instead of Image Caroulse on mobile. The effect increases when looking at Image Carousels by number of first-page results.
Contrary to expectations, SERPs with 10 results did not show any image carousels. Instead, this phenomenon supports the thesis I stated in the last previous that Image Carousels replace an organic result. 67% of mobile SERPs with 9 results show Image Carousels and 58% on desktop.
Comparing mobile with desktop search results for e-commerce brings a couple of interesting differences to light.
First, the differences are strong, especially for search pages with more results.
Second, mobile and desktop SERPs continue to evolve in slightly different directions. Mobile results, for example, show fewer Image Carousels but a lot more PLAs.
Third, Google seems to lean into the fact that users scroll and swipe more on smartphones and is less lenient on making the search results pages shorter.
Again, a lot more research is needed because the SERPs evolve at a rapid pace. If there would be a meta point I wanted to make across all these analyses, it’s that most companies don’t pay enough attention to SERP changes. Staying on top of them is a competitive advantage.