David Houle

“Commercial cellphone use began in the early 1980s, but it took 20 years to go from the first to the billionth cellphone subscriber in 2002. It then took only four years to reach two billion subscribers in 2006, the approximate beginning of the Shift Age. It then took two years to reach three billion cellphone users in 2008, four billion by 2009, five billion by the end of 2010, and 5.3 billion by the end of 2011. As of the writing of this book, there are 7.2 billion people alive today, and approximately 6.1 billion of them have cellphones. If you discount those under the age of eight and those living in remote parts of the world, humanity has now reached almost complete cellphone ubiquity.”
― David Houle, Brand Shift: The Future of Brands and Marketing