What do we talk about when we talk about mobile? Increasingly, the landscape is muddled. Having spent Advertising Week in session after session on mobile media and advertising, both at MIXX and the Mobile Media Summit, not once did a speaker say specifically what they were talking about when using the term "mobile."

To contextualize any discussion of mobile marketing or media these days, the entire arena must be addressed with a much greater level of specificity. Raise this point with people who live and breathe mobile and the first reaction is, "Oh! I get it. You mean whether it's iPad or smartphone, right?"

Only sort of right. Because defining device is just the tip of the mobile iceberg. And let's get one thing straight - straight off: mobile is not as simple as tablet vs. phone. Mobile can encompass laptop computers. Mobile gaming devices. Kindles and other e-readers. Non-smart (dumb?) mobile phones are mobile devices, and so are a panoply of digitally connected gizmos, such as Bluetooth headsets and those NFC-enabled car keys BMW is developing to do stuff in the real world other than unlock your car door (the internet of things - that's a whole other discussion).

While all the above are mobile, they're mobile in extraordinarily different ways. Plenty of mobile advertising is highly geo- or location specific. So do devices such as laptops, without GPS or other location functionality, now qualify as "mobile" within this context? Not for many ads, apps or media. Can the device handle a QR code? That's pretty essential to many of these discussions. Barcode scanners are part of the standard Android deck, but optional add-ons in the iOS environment. Flash works on some of these things, but not on others.

So now that we've narrowed our discussion of mobile media and marketing to a specific device or two, can just we move on? Not so fast. Media and ad formats vary by device, by size, and by carrier. Apps are robust on some platforms, while not available on others. Consumer behavior varies radically not only between devices, but as research is beginning to indicate, on and app-by-app basis even when the device in question remains the same.

Perhaps this inability to reach any level of granularity or specificity is why that elusive "year of mobile" is yet to arrive (unless it's already come and gone?). How will we know it when we see it if the terms aren't defined? It's easy to understand why mobile advocates shy away from fine distinctions. Mobile marketing and media are still nascent - even more so than the rest of digital. Only in a landscape developing this quickly, and with new devices with new levels of functionality coming onto the market seemingly every month, delineations and definitions become only more critical.