By Alec Green

I had one of those ?only in L.A.? moments the other day. I was walking my dog and almost got run over by a teenager skateboarding on the sidewalk while texting on his iPhone. It may be time to extend the hands-free laws to non-motorized vehicles, as well.

We all have such stories of friends, strangers and reckless teenagers focused more on their phones than our health and safety. But these scenarios seem to play out far less with tablets in hand. Coincidence? I think not.

It might be hard to believe, but tablets are not mobile devices and here are four reasons why:

1. Tablets are rarely taken out of the home.
Would it surprise you to learn that relatively few people take their tablets with them when they leave the house?

Sure, tablets are great travel companions, but unless you are constantly traveling for business, the occasional vacation does not consume any impactful tablet time.

According to research from Google, the majority of tablet activity takes place on the couch, in bed or in the kitchen. And as this time of use study shows, tablet searches on Google spike in the evening, just as desktop searches decline.

2. Google says so, basically
A short while ago, Google rolled out a significant change to its advertising platform, AdWords, which it calls called Enhanced Campaigns.

The product enhancement creates a scalable system for managing campaigns across multiple devices.

The release is a huge shift in segmentation strategy because it enables advertisers to segment keywords to smartphones for performance measurement ? but will not allow for segmentation of tablet separate from desktop.

Translation: With Enhanced Campaigns, advertisers will no longer be able to separate tablet devices from desktops.

Performance gains realized from tablet segmentation will no longer be supported.

Even Google is starting to make the distinction between smartphones and tablets because consumers are using the devices very differently.

If the metrics from smartphones and tablets cannot be measured in the same way, then why would we ever lump them into the same category?

3. Advertiser spend on tablets has come at the expense of desktops, not smartphones
In a 2012 Q4 State of Paid Search Report, which tracks a number of key paid search metrics segmented by search engine, industry and device, one of the data points that caught my attention was the breakdown of paid search spend by device.

Overall, share of spend on tablets and smartphones grew 79 percent year over year. And fourth-quarter 2012 was the first quarter in which advertisers? spend on tablets exceeded the spend on smartphones.

You can see similar growth numbers when looking at paid clicks.

According to the study, 9.8 percent of paid clicks came from tablets and 13.6 percent came from smartphones.

Tablets continue to show strong quarter-over-quarter growth, while smartphones were relatively flat, suggesting that tablets could be cannibalizing search clicks from desktop.

4. Most tablets are Wi-Fi connected, not through cellular
Analyst Chetan Sharma covers the mobile data and handset market in the United States and found that of the roughly 48 million active tablets active in the U.S., only 10 percent are cellular activated. And sales of Wi-Fi-only tablets are growing at a faster rate than cellular-activated tablets.

This data is consistent with a study by Localytics that found 90% of iPads were WiFi only and 6% of all iPad sessions were via a cellular network. For 3G-enabled iPads, 55% of the overall usage comes from WiFi. For 4G-enabled devices, the WiFi percentage jumps to 64%.

Think about this: if only 10 percent of tablets are cellular connected, and only 6 percent of Web activity on tablets is coming from 3G or 4G networks, are tablets appreciably more ?mobile? than a laptop?

The answer is still yes.

Tablets are easier to transport and quicker to connect. But more often than not, tablets seem to be acting as a replacement or supplement to the traditional home computer ? the device the search engines still refer to as ?desktop.?

So can we all agree to stop lumping tablets and smartphones together as ?mobile devices??

I understand that ?non-desktop? or ?non-PC? does not have quite the same panache. But categorizing smartphones and tablets together under the broad category of ?mobile? seems misleading.

In the age of mini-tablets, phablets, convertibles, and smartwatches, the lines between these devices are becoming increasingly blurred and the accepted categories of ?desktop, tablet, and smartphone? will need to be updated.

But until I get run over by a skateboarder playing Angry Birds on his iPad, I will not call tablets mobile devices.

Alec Green is vice president of marketing at The Search Agency, Los Angeles. Reach him at .