"The internet will have added its second billion users over a span of about eight years, a testament to its universal appeal and its availability," said John Gantz, chief research officer at IDC.
"These trends will accelerate as the number of mobile users continues to soar and the internet becomes truly ubiquitous."
Net-enabled mobile devices will help drive the global online trend, surpassing the desktop PC as the primary means of accessing the internet by 2012, according to the report.
China, which last year overtook the US in terms of overall internet users, will see its online population increase from 275 million today to 375 million in 2012.
Revenue-generating opportunities will be driven by consumer and business-to-business purchases, and one billion global online shoppers will account for US$1.2tr worth of business-to-consumer transactions by 2012.
However, it is in the business-to-business arena that IDC forecasts the most spectacular growth rates, generating estimated worldwide revenues of $12.4tr over the next four years.