U.S. mobile commerce sales hit $24.66 billion in 2012, up 81% from $13.63 billion in 2011, research firm eMarketer says. EMarketer counts sales made on smartphones, tablets and other mobile devices such as Apple Inc.’s iPod Touch. It excludes travel and ticket sales.

U.S. m-commerce sales will rise 55.7% to $38.40 billion in 2013, 35.8% to $52.17 billion in 2014, 30.9% to $68.29 billion in 2015, and 27.2% to $86.86 billion in 2016, eMarketer forecasts.

Retail sales on smartphones and tablets accounted for 7% of U.S. e-commerce sales in 2011 and 11% in 2012, eMarketer finds. They will represent 15% of e-commerce sales in 2013, 18% in 2014, 21% in 2015 and 24% in 2016, the research firm predicts.

“EMarketer’s m-commerce forecast reflects a confluence of three trends,” the research firm says. “First, the expanding number of smartphone shoppers whose behavior affects commerce in all channels; second, the growing number of smartphone buyers who enjoy the immediacy of purchasing through their phone and are expected to generate just over one-third of m-commerce sales this year; and third, the rapid rise in tablet shopping, which will produce the bulk of m-commerce sales over the next four years.”

Of the $24.66 billion in mobile sales in 2012, $13.86 billion, or 56.2%, came from tablets; $9.86 billion, or 40.0%, came from smartphones; and $0.94 billion, or 3.8%, came from other mobile devices, eMarketer says.

Of the $38.40 billion in mobile sales predicted for 2013, $24.00 billion, or 62.5%, will come from tablets; $13.44 billion, or 35.0%, will come from smartphones; and $0.96 billion, or 2.5%, will come from other mobile devices, eMarketer forecasts.

EMarketer analyzed more than 120 data sets from dozens of research sources that track commerce sales and consumer behavior—whose figures are each evaluated by eMarketer based on their respective methodologies, definitions and historical accuracy—before forming its forecast, the research firm says.