Keywords on Mobile: Not Comparable to Desktop

Last week Google confirmed that smartphone searches now exceed desktop searches in 10 countries. WOW. That was fast. Despite this fact, many brand marketers still haven’t figured out what to do with mobile.

The direct conversations that brands have grown accustomed to via desktop just aren’t there, so new solutions are being created. While that struggle continues, I find one of the best ways to overcome the mobile challenge is to understand consumer behavior on various devices. We all know that in order to be the best marketers, we have to do what is best for our customers – this includes delivering valuable experiences.

One way to understand consumers in search is to study how their behavior impacts keyword queries. Are they searching the same way across devices? I looked at the type of queries consumers were using in a previous article. It showed a lot of growth in question based queries on mobile and tablets, which suggests voice search has started to alter the way people search for information. This time, I took a look at the number of keywords that are in a search. The goal is to understand how they impact the results brands see for various metrics.

I pulled data across multiple clients and indexed the actual numbers to not provide specific metric ranges. This data can be pulled from a search terms report in Adwords – run this formula (=LEN(Q2)-LEN(SUBSTITUTE(Q2,” “,””))+1) – on the keyword column to get the number of words in a query.

I first wanted to understand click-through rates (CTR). How descriptive are consumers when they search and how often do they click the results? What I found was mobile CTR was highest for shorter keywords. Once the search term got beyond three words, the CTR was well below the index and only went down as the number of words in the query went up. Desktop had a fairly similar path, but the drop off was not nearly as significant, suggesting that longer queries, when you have a keyboard, lead to similarly valuable results.


Next, I wanted to check out how keywords converted. This showed a similar pattern that you might expect. When consumers included more keywords in their query the conversion rate went up. This suggests that as the specificity goes up, consumers have deeper intent to buy. The big variance in conversion rate was seen with mobile and single keyword searches. In this data set there are a fair amount of products that are pretty simple: if you want to buy shoes from Nike you can search for “shoes” and get to what you wanted on mobile. The goal is to keep things as simple as possible on mobile, more so than on desktop, where something a little more complex is easier to complete.


Finally, I took a look at cost per click (CPC) by keyword count. I think this one shows more about how advertisers optimize for keywords vs. the consumer perspective, but they obviously align. For example, mobile CPCs greatly increased as the keyword length went up, which aligns to the conversion rate data seen in the previous chart. The better the conversion rate, the higher the CPC bid can be set.


I find this type of data fascinating. Every so often you have to be able to take a step back and look around the landscape. Is what you were doing in the past still working? Have consumers shifted, given market or technology shifts, so that your plan at the beginning of the year did not account for now? Mobile is the biggest mover that we’ve seen in our industry in a long time, and the trend isn’t slowing down. I encourage you to start thinking “mobile first”, like many of your consumers already are. 

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