Brad Geddes / PPC Geek
Official Google Ads Seminar Leader.
Author of Advanced Google AdWords.
Co-Founder, Adalysis.
(703) 828-5811‬
Brad Geddes's Theories on Marketing Learn How To Test Mobile & Desktop Ads Correctly

Learn How To Test Mobile & Desktop Ads Correctly

Last year, Mobile search surpassed desktop search in terms of total queries. The statements of  ‘next year is the year of the mobile device’ have passed. Mobile has arrived.

However, most account we view still treat mobile and desktop users the exact same. If there’s a variance, its because of a mobile landing page – not because the account owner has thought about how mobile and desktop users behave and what they wish to accomplish by device.

As mobile and desktop users are often looking to accomplish different tasks based upon the device type; you should test ads differently based upon the user’s device.

However, first we should examine the concept of ‘effective device’ so you understand where your ads are really showing.

Examining Effective Device

With Google and Bing, you can designate an ad as ‘mobile preferred’.


However, that ad might not only be on mobile devices based upon the other ads in an ad group. For instance, if you only have mobile preferred ads in an ad group; then those ads are displayed on desktops and tablets.

If your ad group only contains desktop ads and your campaign is showing on all devices, then your desktop ads are effectively ‘all devices’. This leads us to an important concept: effective device for ads.

There are three possibilities for effective device:

  • All devices: These ads are showing on all devices
  • Mobile: These ads are mostly showing on mobile devices
  • Desktop: These ads are mostly showing on desktops and tablets

I do use the word ‘mostly showing’ on purpose as it’s possible due to various technology reasons that your mobile ad might show on a desktop or vice versa. This doesn’t happen often, but it does on occasion.

Therefore, to control ad serving by device you need at least one desktop and one mobile device ad in an ad group. To test by device, then you need at least two desktop and two mobile preferred ads in an ad group.

Determining Your Effective Devices

There is not an easy way in AdWords to determine what devices your ads are running on nor to determine if you are testing your ads by device.

The easiest way to get started in understanding this information is to follow these steps:

  • Navigate to the ads tab in your account
  • ‘Customize the columns’ and ensure that device preferred is selected
  • Download the data
  • Create a pivot tablet from the data
  • In your Row Labels; select ad group (if you have a large account, you can select both campaign and ad group)
  • In your Columns, choose device preference
  • Finally, your values should be counts of ads

Now, that will just give you a bunch of numbers that are hard to read; so to make the pivot table visual, add conditional formatting to the pivot table:

  • If column is 0, then color it red
  • If column is 1, then color it yellow

The legend of effective device:

  • If the ‘all’ device column is red (so there are no desktop ads); then your mobile ads are showing on desktops; meaning your mobile ads have an effective device of ‘all’.
  • If the mobile column is red, that means you don’t have mobile ads in the ad group and your desktop ads are showing on mobile devices

The legend for testing:

  • If any column is yellow, then then you have an ad of that type, but you aren’t testing in that ad group



Where to Start Creating Ads

There are two places where you will want to sort to determine where to create ads:

  • Cost: test where you are currently spending the most money
  • Impressions: test where you have the most opportunity

The easiest way to do these sorts is to:

  • Add spend and cost to the pivot table
  • Copy the pivot table data (with formatting) to a new sheet
  • Filter by the ‘all device’ column and only include cells that are highlighted red (your mobile ads are showing on desktops)
  • Sort by spend or cost highest to lowest

That will ensure that you have desktop ads in all your ad groups. Now repeat the process filtering by the mobile column by ‘red’ or zero mobile ads.

Once you have at least one ad by device type by ad group; then you are controlling ad serving by device.

Next, you will want to repeat these steps for the columns that are yellow so you can make sure you are testing your top ad groups for each device.

Automating the Process

This process will give you a snapshot of your ad and testing information in the account at the moment you created and analyzed the pivot table. However, it won’t give you this information automatically until you create the table and analysis again.  In addition, just because you are testing doesn’t mean you are declaring winners.

If you want to easily:

  • Receive alerts by device type
  • Have a simple way of sorting this data by cost or impressions (or other metrics)
  • See when you have ‘winning ads’ by effective device

Then please take a look at which will make this processes simple and automated.


To be a true PPC expert, you need to move past how to just create and test ads across all devices. You need to think about how users interact with your ads on each device and across devices. It’s useful to initially lay out some hypothesis about users and do multi-ad group testing. Then once you’ve learned at a high level how users interact with your ads, move towards testing your ads by effective device. If you want to see some lessons on how to do this; take our 7 day free trial here at Certified Knowledge and watch the videos on ad testing.

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