Smartphones will continue to gain traction among US mobile users over the next few years, with the number of consumers owning a device more than doubling from 93.1m at the end of last year to 192.4m by 2016, or 58.5% of the population, according to eMarketer.  This marks a compound annual growth rate (CAGR) of 15.6% between 2011 and 2016, considerably higher than the CAGR of mobile devices generally, which will remain relatively flat at just 1.8% between 2010 and 2016.

While smartphone penetration will reach 36.6% this year, eMarketer predicts that figure will grow to encompass more than half the US population by 2015, driven by demand for Apple's iPhone and devices running on Google's Android operating system. Among existing mobile users, penetration will near 50% this year, but growth rates are set to even out as the market begins to mature.

This growth comes as wider mobile usage begins to flatten, with mobile users growing at a CAGR of just 1.8% between 2010 and 2016, with devices beginning to hit saturation point. It is likely that the higher growth rate of smartphones is due to existing mobile users converting to higher-end devices, with separate comScore data indicating that consumers are making greater demands of their phones, such as app access and web browsing. The growth also fits with a wider global trend of greater shipment volumes, with connected device shipments set to near 2bn by 2016, according to IDC.

The news comes as US device manufacturer Apple saw its share price blow past Google's to USD641 per share, driven by continuing consumer demand for its mobile devices such as the iPhone and iPad. According to eMarketer, growing interest in tablet devices has also boosted US mobile connections in the US, with subscriptions rising 11.6%. With mobile connections already outnumbering the US population, it is likely that the popularity of tablets is driving the higher growth rate.