Ever use your smartphone or tablet while watching television? Ever read an article halfway on your desktop computer, and then rest on your phone later? And have you ever noticed that a company whose site you checked out on your phone is suddenly appearing in ads while you browse the web on your laptop?

The proliferation of web-connected devices and the modern propensity for us to own (and use!) several of them at once has not been lost on web publishers or advertisers. As mobile readership continues to grow, publishers respond by building mobile versions of their sites with layouts that make sense on small screens, navigation that relies on tapping and swiping, and page weights that don't necessarily rely (yet) on broadband speeds.

Users are Individuals, Not Devices

Furthermore, web services, unsurprisingly Google at the forefront, have become adept at tracking your behavior as you hop from device to device. Google Chrome shares information across every instance of the browser among your devices. Save a bookmark on Chrome on your MacBook, and you'll find it when browsing the web on your Samsung Galaxy S4.

Advertisers are understanding that a user's interests and patterns of behavior don't change radically when moving from phone to tablet, although the constraints of the form factor, input, screen orientation, bandwidth, and typical use cases can make some differences understandable (e.g. watching lots of bandwidth-hungry video is more common when you're on a wifi connection at home than while relying on a mobile data signal on the run). 

Ad Functionality Differences

Differences between mobile and desktop environment technology mean that not all functionality is available or ideal for use universally. Some examples:

  • Location services: While some desktop browsers can approximate location, they lack the preciseness of GPS-enabled mobile devices. Zoomed-in maps and geofencing functionality are mobile-only at the moment.
  • Forms: While filling out forms on the phone is possible, it is more than a major annoyance.
  • Video: Flash video will run into problems on iOS devices, and because video requires a ton of bandwidth, their use should be limited on all devices that rely on mobile data.  

Device Orientation

Another wrinkle with mobile devices is that the screen orientation changes often, changing from portrait to landscape and vice versa on the fly when the user turns the device 90°, something that is never an issue with desktops and even notebook computers. Without some accommodation within an ad's response, you run the risk of having your ad ignored when it's in the "wrong" orientation.

Flite provides a device orientation trigger that allows the user to specify what happens when a touch device switches from a vertical to horizontal, or the other way around. For example, the expansion while in portrait mode might have a different aspect ratio and layout than it would have while in landscape mode. The example below illustrates how this might look:

The same ad detects the orientation of the device and displays a different expansion depending on it. 

Responsive Design

But since there is nothing approaching standard dimensions with screens these days, publishers are increasingly turning to responsive layouts that can handle an infinite range of dimensions and aspect ratios. A responsive site/design automatically adapts to the dimensions of a device screen, usually by establishing breakpoints for the three predominant layouts (for generalized desktop, tablet, and smartphone aspect ratios) and logic that shrinks or grows the page between those breakpoints to accommodate the screen size.

Advertising can certainly follow the same idea. In fact, the IAB has published a report exploring the concept and possible implementation, and, in concert with firm ResponsiveAds, a live demo site that allows you to see how a display ad that adheres to responsive principles behaves as you resize your browser window.