Apple launched its most profitable product iPhone 5 years ago. Until June-12, it has sold a whopping 85.9 Mn units generating revenues of $51 Bn. Here is how various models of the iPhone that have evolved and how they have been sold,
2007 - iPhone Launched - Sold 3.2 Mn Units
2008 - iPhone 3G launched by AT&T - Sold 7.02 Mn Units
2009 - iPhone 3GS launched by AT&T - Sold 10.18 Mn Units
2010 - iPhone 4 Launched by AT&T - Sold 14.12 Mn Units
2011 - iPhone CDMA launched by Verizon in Q2, while iPhone 4S is launched by AT&T , Sprint - Sold 32.37 Mn units
2012 - Till June-30th, iPhone Sold 19.02 Mn Units awaiting the launch of iPhone 5.
In India, by courtesy of Aircel, iPhone 3GS is the affordable SmartPhone today, otherwise iPhone 4s etc are way too expensive to be handled in the Indian market.