According to the market analysis firm Canalys, nearly 500 million smartphones were shipped worldwide in 2011, compared to (only!) 415 million PCs. The predictions for smartphone sales in 2012 are even higher.

Correspondingly, a recent Nielsen report indicates that smartphone penetration of the US market has almost reached 50%. Not surprisingly, smartphone ownership is most prevalent among higher earners and younger adults. What is remarkable is the prevalence of smartphone ownership across all age and income groups.

Since smartphone owners represent a large proportion of the most desirable consumer demographic, having a mobile strategy is no longer an option — it is an imperative. So what should marketers do?

First, we need to understand what consumers are doing on their mobile devices. According to Adobe/Omniture statistics, the main mobile activity is consumption of media and entertainment. Consumers are also shopping via mobile. Let’s take a closer look:

Social media consumption is the most frequent mobile activity, with most active users accessing social media on a daily basis. Mobile entertainment includes reading, listening to music and of course, playing games. Games are currently the most popular app category for both smartphones and feature phones. When out and about people seek information about local events, dining and entertainment opportunities.

Shopping on mobile devices is still in an emerging activity, but it is gaining traction, and is predicted to increase dramatically in the next year. At present, people are more likely to research potential purchases and compare products, than actually make the purchase via their mobile device.

Engaging people through the activities they frequently enjoy has the greatest chance of success. So how do we engage consumers through social media, entertainment and shopping? Here are a few ideas:

We recently blogged about how businesses can connect with consumers on social media channels. Other avenues are open as well. Gaming is popular across all market segments – a brand-centric or co-branded game can be targeted to a very specific audience or a broad spectrum of players. Likewise, sponsoring of local events will reach mobile consumers as they’re scouting nearby activities.

Retailers wanting to engage shoppers should indulge, and even facilitate, their research and comparison activities. Consumers are currently making more purchases on mobile sites than mobile applications, perhaps because comparisons are easier. For businesses entering the mobile arena, a mobile-optimized site may be the best investment.

Retailers that make product reviews easy to access and quick to comprehend will earn the good will of their customers. For smaller brands, consumer reviews and social media support (e.g., Likes) can provide a leg up against the most established brands. Transparent pricing information, multiple product images, and an easy checkout process are of primary importance to a majority of mobile customers. Indicators of site security will reassure wary mobile shoppers. These are customer experience features that will continue to deliver for years to come.

Regardless of the products or services your business offers, the time is right for a mobile strategy. Engaging consumers means meeting them where, when and how they live, and today, that’s on their mobile devices.