• by Mark Walsh  @markfwal, June 11, 2014

The U.S. will be among nine countries where smartphone adoption exceeds more than half the total population this year. That figure will reach 15 countries, representing about 500 million people, by 2015, according to a new eMarketer forecast.

By the end of 2014, the research firm expects 1.76 billion people to have and use smartphones monthly, up more than 25% over the prior year. Just under a quarter of the world’s population will use smartphones this year, and by 2017, more than a third.

The estimates for smartphone users account for the number of people who own and use the devices, regardless of how many smartphones an individual might have.

Consumers in Asia-Pacific will account for more than half of all smartphone users this year, at 951 million. China alone will make up 521.7 million users this year—by far the most of any country—but won’t hit the 50% tipping point until 2018. Japan will do so this year.

Western Europe, will total 196.6 million smartphone users this year, with the U.K. and the Netherlands joining the three Nordic countries in passing the 50% mark. Close behind will be the U.S. with, 163.9 million smartphone users. To the north, Canada is expected to reach majority smartphone ownership next year.

eMarketer says it bases its forecast on quantitative and qualitative data from various research firms, government agencies, media outlets and company reports, weighting each piece of information according to methodology and soundness.

Because of growing saturation, the rise in smartphone shipments is projected to slow this year. Shipments will increase 19.3% to 1.2 billion this year, but that’s down from 39.2% in 2013, according to IDC. By 2018, annual growth will fall to 6.2%.

More smartphone users globally means more people using apps. But people can be notoriously fickle when it comes to apps. One in five are opened only once before getting pushed aside, according to separate research today from app analytics and marketing firm Localytics. The firm says that’s actually an improvement from 26% of apps getting the one-and-done treatment four years ago.

The study also found 39% of all apps are used 11 or more times. Sports and game apps have the highest abandonment rates, while weather and social networking have the lowest. When it comes to smartphone platforms, Android has surpassed iOS in app engagement, according to Localytics. Some 45% of Android apps are opened 11 or more times versus 34% on the Apple operating system.

The firm suggested that could be a result of many Android models having larger screens than the iPhone, making them more suited to playing games or browsing news content. Localytics says it collects data from mobile and Web apps across more than 1.5 billion devices and 25,000 apps.

"Smartphone User in London" photo from Shutterstock.