The panel on online publishing and mobile apps at OMMA Global got me wondering: how many iPhones have been sold? Turns out, a whole friggin bunch. Worldwide, 47.8 million iPhones had been
sold by the end of 2009, and the number is expected to rise to 55.5 million by the end of the first quarter of 2010. In the U.S. market, 21.6 million had been sold by the end of 2009; if
each unit sold remained in use and represented one mobile subscriber, and there was no overlap with other mobile subscriptions, that would represent 9.3% of the 234 million mobile
subscribers in the U.S. in December 2009.  Although I couldn't find reliable projections for the first quarter of 2010, for the full year 2010 it's projected Apple will sell
another 15.8 million, for a total 37.4 million by year end, or 16% penetration. Meanwhile it's estimated 500,000 new mobile apps will be introduced in 2010(!)
