More Americans will be accessing the Internet using mobile devices than through PCs or other wireline devices come 2015. The number of mobile Internet users will grow at a compound annual growth rate (CAGR) of 16.6% between 2010 and 2015 as smartphones begin to outsell feature phones and tablet sales explode, according to the latest release of IDC’s, “Worldwide New Media Market Model” report.

Smartphone growth, and to an even greater degree, tablet growth will be so strong that the number of people using PCs to access the Internet via wireline connections will stagnate and then slowly decline, first in the US and then with Western Europe and Japan following close behind.

“Forget what we have taken for granted on how consumers use the Internet,” said Karsten Weide, research vice president, Media and Entertainment. “Soon, more users will access the Web using mobile devices than using PCs, and it’s going to make the Internet a very different place.”

Other findings in IDC’s New Market Model report include:

  • Worldwide, the total number of Internet user will grow from 2 billion in 2010 to 2.7 billion in 2015, when 40% of the world’s population will have access to its vast resources.
  • Global B2C ecommerce spending will grow from $708 billion in 2010 to $1,285 billion in 2015 at a CAGR of 12.7%.
  • Worldwide online advertising will increase from $70 billion in 2010 to $138 billion in 2015, with its share of total advertising across all media growing from 11.9% to 17.8%.