According to an article in mashable.com, there is some phenomenal growth in mobile subscriptions around the world:

“By 2004, there were more mobile subscribers in the developing world than in developed countries, and the gap has been widening ever since. In 2012, Jana estimates that of the 6.5 billion mobile subscriptions on Earth, 5 billion are in emerging markets. The World Bank estimates that 75% of the people on Earth have access to a mobile phone. According to the McKinsey Quarterly, 3 billion people are projected to move into the middle class in the next twenty-five years. Right now their mobile devices are in some respects the most direct way to reach them.”