Why Mobile Matters: Understanding Cross-Device Performance

My last post discussed the ever-growing significance of mobile advertising and the importance of its incorporation into every advertiser’s online marketing strategy. This post will drill down into one of the most common issues advertisers run into when trying to assess the value of mobile for their business.

Cross-device use has become both a behavioral reality and a big challenge for advertisers. That is, users commonly start enter the conversion funnel on on device — their smartphone or work computer — and complete their purchase on another, such as their home desktop later that evening. Another common scenario involves users searching for information on their smartphone and using that information to complete in-store purchases.

Users rely on their devices to get information in a number of ways:

  • Getting directions and hours of operation info for in-store visits
  • Comparing offline offers with online offers while in-store
  • Researching products when considering offline purchases
  • Researching products on one device and later converting on another

While these actions can be difficult to tie to actual conversion actions, there are a number a tools and strategies you can employ to get a better picture of your users’ cross-device performance.


1.) Use personally identifiable information

This may be obvious, but if you have a sign-in requirement on your site or any other means of collecting unique user data you can track behavior across multiple visits. Assess the device type used to volunteer the information in the first place against the device type used to convert. This may necessitate some additional tracking tweaks in order to tie the device type to the each unique sign-in/up action.

This works for offline sales as well if you can collect the user’s information via your website and later connect it to an in-store purchase. When using this method, be sure to base conclusions on statistically significant amounts of data.


2.) Try turning off your mobile campaigns for two weeks

This solution isn’t perfect but it’s a great way to get a real-world idea of what mobile’s doing for you. Just turn mobile targeting off for a few weeks. Obviously, the ideal amount of time depends on how much traffic your ads receive, but you get the idea. If you’re not seeing mobile conversions but are seeing a big drop in desktop conversions without mobile serving, that’s a strong indication that mobile is playing an important role behind the scenes.


3.) Use AdWords Cross-Device conversion metrics

AdWords recently released the beginnings of a solution to this issue by producing a suite of metrics that estimates how many cross-device conversions you’re likely to be receiving based on sample data from users who are signed into their Google account.


4.) Monitor mobile behavior in Google Analytics

Because mobile is often a driver of more “top-funnel” traffic, it can be telling to look at how your mobile users are behaving on the site. Take a look at their interaction with micro-conversions — e-book downloads, mailing list signups, etc. — to get an idea of the level of user engagement. A high level of engagement may correspond to a higher likelihood of mobile users returning via another device for another look.



  • Cross-device tracking is still in it’s infancy, but better solutions are sure to come quickly.
  • Mobile often serves as a key driver of “upper funnel” traffic.
  • Use information volunteered by customers to help develop insights.
  • Use AdWords Cross-Device tracking, but you should might want to take the data with a grain of salt, at least for now.
  • Use Google Analytics to understand mobile behavior and aid in developing cross-device assumptions.
  • Don’t be afraid to see what happens when you shut off mobile for a little while. The insights may end up been much more valuable than any short term loss in conversion volume.