Just under half of the total US population will be using the internet via mobile by 2015, according to the latest estimates by eMarketer.  This year 97.3 million Americans (31%) will access the internet via their mobile phone at least once per month in 2011, an increase of nearly 25% from last year. By 2015, this number is expected to reach over 156 million.

Increased smartphone penetration will be responsible for most of the growth in US mobile internet usage:

• smartphones will reach 38% of mobile users and 28.8% of the overall population by the end of 2011
• the number of smartphone users is expected to increase nearly 50% this year
• smartphone user growth will continue at a steady double-digit pace through 2015
• just over 90 million US consumers will own a smartphone by the end of this year; that number is expected to rise to nearly 150 million in 2015

The eMarketer estimates of mobile internet usage include people of any age who access the internet from a mobile browser or installed application, at least once per month.