Research firm AppNation forecasts a dramatic increase in the overall app economy in the U.S. over the next four years. The AppNation report predicts that the combined value of paid apps, app-enabled purchases of goods and services, and in-app advertising will double to $151 billion by 2017. While smartphones and tablets largely drive today’s app economy, innovations with smart TVs and connected cars are expected to help drive future app commerce.

“According to the research firm, the largest segment of the so-called app economy is app-enabled sales of physical goods and services, which accounted for about $45 billion of the nearly $60 billion total at the start of 2013,” reports Computerworld. “By the middle of this year, the $60 billion total had reached about $72 billion, and that figure is expected to more than double to $151 billion in 2017.”

“Despite the massive popularity of apps and a saturated marketplace in the U.S., the overall growth rate in the app economy is still accelerating and will [continue to accelerate] until at least 2015,” said Drew Ianni, CEO of AppNation. “With the number of apps used per day by U.S. consumers still expanding, and as time spent on mobile devices shifts more to use apps versus other media, it is clear that there is still a lot of runway ahead of and across all key sectors of the app economy.”