Brazil, Russia, India and China -- collectively known as BRIC -- represent 43 per cent of the world's population and will profoundly change the way both the mobile telecommunications and the marketing industries operate.

eMarketer has estimated that BRIC will account for nearly 1.2 billion mobile phone subscribers this year. Beyond the scale involved, BRIC's growth is a game changer because mobile will be the primary interactive screen for a new generation of consumers.

"Mobile is not simply viewed as an extension of the Web in BRIC, as it is in the US, Western Europe, and parts of Asia/Pacific," said John du Pre Gauntt, senior analyst at eMarketer and author of the new report, Mobile BRIC: Extreme Growth Ahead. "Mobile is the Internet for an increasingly large and attractive consumer segment -- an important distinction for marketers to keep in mind."

eMarketer projected that the BRIC countries will account for more than 1.7 billion mobile phone subscribers by 2012. Of that number, more than 680 million subscribers will access the mobile Internet.

"As these huge populations within BRIC accumulate disposable income, they are poised to form interactive relationships with local and global brands primarily through the mobile phone", Gauntt said.

With PC and broadband penetration far below that of mobile, marketers and mobile operators find themselves in uncharted territory -- needing to serve new populations untethered by the legacy of the fixed-line Internet.

"The scale facing marketers cannot be understated", Gauntt said.

Five of the world's 10 largest cities are located in BRIC, along with four of the five top markets for new mobile subscribers.

"These markets already account for the majority of new growth for the mobile telecommunications industry, which is only one of the value-added service and marketing sectors affected by the growth of BRIC," Gauntt noted.

Len Rust is publisher of