Mobile is important, right? There are all those many hundreds of millions of people who can use their smartphones and tablets on the Internet to do research, view videos, and see consumer product recommendations. Smart marketers and entrepreneurs know that mobile is a must.

But that's often just a vague sense, like so many trends in business that exist because enough people point to them and say, "Look, there's a trend!" Consultants, vendors, and would-be gurus all want business owners and managers to buy into whatever it is that they're selling.

Here is some data coming out of AOL and University of Virginia researchers about how consumers are using mobile. (Disclosure: I write for AOL Jobs, among other places, though I learned of this independently.) What makes it interesting is two-fold.

First, someone crunched through a hell of a lot of data: 500 billion online ad impressions in travel, retail, auto, and telecom and 100 million conversion events across all devices. The conversion events were booking a hotel, flight, or car reservation for travel; making a purchase for retail; finding a local dealer, requesting more information, or configuring a car for auto; and purchasing of new plans and devices for telecom.

Although volume doesn't necessarily make information representative of markets as a whole, take an honest look at enough of it and, almost by definition, you have something that is of interest to businesses. Second, some of the results show that mobile may be taking off faster than most people, including industry cheerleaders, expected.

Mobile is important for conversions

In these four industries at least, 31 percent of conversion events happened on a mobile device, and that was up by 28 percent from the previous year. Telecom had the highest mobile conversion at 37 percent, while the lowest was 20 percent for travel. If you aren't advertising smartly on mobile, chances are you're giving away a chance to do business.

Mobile is big at home

Mobile is supposed to be when people are on the go. But apparently much of the public's get-up-and-go got up and went. Consumers spent 25 percent of their online time at home on a smartphone or tablet and three-quarters of all mobile ad impressions happened at home. That can affect how you structure a marketing program.

iPads really sell

You knew that iPads were the biggest seller in the tablet space, though devices running Android are quickly catching up. But when it comes to selling products, iPad is king by a long shot. About 65 percent of mobile conversions happened on tablets and 85 percent of those happened on iOS devices. No way to know whether that is due to the total volume that has shipped or if iPad owners are more likely to respond to advertising.

It's impossible to know whether there is a novelty factor at work--people taking action because the whole process of using a tablet is still relatively new, which would leave room for conversion rates to drop over time. However, the prudent approach for entrepreneurs for now is to make sure they treat mobile as an important marketing channel and one often used at home, so don't assume that mobile is only good for catching people when they are near your establishment.