• by Mark Walsh  @markfwal, March 29, 2012

As smartphones and tablets have spread quickly in the last two years, some clear differences have emerged in usage. People turn to tablets mainly at home, while smartphones are used on the go, as well as at home. Tablets lend themselves to “lean-back” media consumption, while smartphones are geared to utility.

The differences in how the devices are used, and who’s using them, impact how advertisers should approach them, according to a new Forrester report. It lays out separate marketing tactics for tablets and smartphones across a range of areas, including apps, display advertising, games and search.

The main message is not to lump them together as mobile platforms, but tailor mobile initiatives according to the relative strengths of each device. That means marketers should not count on building one app for both screens. The report points out that Citi’s Private Banking app, for example, is geared to the tablet, since it offers deep market analysis better suited to reading at leisure on a bigger screen. 

Robitussin’s Relief Finder app, by contrast, is designed for smartphones because people use it to find relevant products while browsing store shelves. The same goes for mobile Web sites. Marketers should not try to send smartphone traffic to a site not optimized for mobile, or tablet traffic to a site geared to mobile phones.

“For example, a tablet user viewing a site designed for smartphones can’t click to call and probably doesn’t need driving directions, but is interacting with a larger display that can therefore feature more content and controls,” noted the report authored by Forrester analyst Elizabeth Shaw. Without matching the experience to the device, marketing opportunities are missed.

When it comes to search, mobile is expected to contribute 25% paid search this year, according to a Marin Software estimate. But Forrester advises a separate search strategy for smartphones and tablets. Because the form has smaller screens and are used more on-the-go, search ads should be kept simple, with features likes site links, local offers and click-to-call. Ads on tablets are better suited to features like click-to-download because of their larger screens and lean-back use at home.

On the display side, click-through rates on both smartphones and tablets are both higher on a PC, making display ads a viable option for both. But on smartphones, in particular, companies should ensure ads don’t get in the way of what they user is trying to accomplish on the device.

Gamers are also popular on both devices, with brands like 7-Eleven and Old Navy finding high engagement with in-game advertising, according to Forrester. Gaming giant Zynga publishes top social games like Words with Friends and FarmVille for the iPad, iPhone, and Android phones and tablets, offering opportunities for sponsorships and in-game ads.

Because of their larger displays and often faster connections via WiFi, tablets are naturally better suited to watching video. About 52% of tablet owners watch video on their devices compared to 46% of smartphone owners. According to Nielsen data released last October, about 40% of both groups use their devices while watching TV.

Smartphones do have one big advantage over tablets -- they’re simply more ubiquitous -- a key factor when considering reach. A new estimate from Nielsen today puts smartphone penetration at half of U.S. mobile users. A recent Pew survey found tablet adoption doubled over the holidays to almost 20% of adult Americans, while comScore estimates 15% of mobile users now have tablets.