Why do mobile ads average a $1.30 CPM while television commercials average more than twenty times that ($29 CPM)? Sure, a 30-second television spot provides a richer sensory experience, but that's quite a multiple. Some suggest that the heavy discount mobile advertising still incurs is that marketers haven't yet settled in on mobile environment metrics that are meaningful to advertisers. Considering that engagement metrics for interactive desktop ads are just now coming into their own, maybe we can afford to be a bit patient - measuring mobile engagement should follow suit.

But what's worth measuring, and how do you do it on a mobile device? Some desktop actions, like hover (mouseover), don't have obvious analogs on smartphones and tablets. How do you know if a mobile user has consumed a brand's message?  

Some mobile user actions are trackable, albeit in a different way from those using a mouse or trackpad. And others aren't quite enabled yet, but technological advances hint at what might be possible.

Mobile Interactions Measurable Today

Although not the same as desktop interactions, most mobile interactions tracked today mirror those that we've seen in computer browsers before. For example:

  • Opening an expansion: Instead of a click or hover, either a tap (touch) or swipe (drag) on mobile devices.
  • Starting a video or unmuting an autoplay video 
  •  Swiping through items in a carousel, slideshow or pagination
  • Selecting or opening items in a list, primarily RSS, Twitter, or Facebook feeds
  • Pressing a call-to-action button: "learn more", "see examples", form submissions, etc.
  • Viewing an image or map in detail by pinching, zooming, or swiping (for 360° viewers)
  • Closing or dismissing expansions, notifications, and other options, typically by tapping or swiping

Advertisers therefore have a number of interactions to measure, and can judge the relative success of an ad by its interaction rate and engagement rate figures against benchmarks.

Time on unit is also relatively easy to measure, by calculating the duration between first and last interaction, or, if an expansion is involved and user-initiated, by simply subtracting the time of closing from the time the expansion is opened.

Mobile Interactions Measurable in the Near Future

Although the equivalent of mouse/pointer tracking isn't possible with a touch device, the proliferation of front-facing cameras and gyroscopes on smartphones should enable something even better: eye tracking, or at least a technological proxy for it. Samsung's latest smartphone, the Galaxy S4, boasts a number of "smart" features prompted by a user's gaze at the device. For example, Smart Pause will automatically pause a video if the phone, through face detection technology, detects that you've taken your eyes off your phone.

Even more interesting is a feature called Smart Scroll, in which a page can automatically scroll if the phone determines you are approaching the bottom of the page, by calculating the angle at which you move your head and the phone. Although it's unclear how effective the feature is or whether users like it enough to keep it enabled, there is technology that can see approximately where your eyes are, at least along the vertical axis.

The extent to which mobile advertisers might be able to know when a user is actually paying attention to a mobile screen ad would make a big difference, possibly enough of one to see that enormous CPM discrepancy between mobile and television ads evaporate. Because while mobile screens are a lot smaller, we use our phones surprisingly frequently and in a much more interactive, intimate way, and while we use our phones while watching TV (the second-screen phenomenon), the inverse isn't the case.