The market size listed here is the number of mobile phones sold worldwide in the third quarter of 2010, of which, 19.3% were smartphones, as we saw in our last market size entry.

Geographic reference: World
Year: 3rd Quarter 2010
Market size: 417 million units
Source: “Gartner Says Worldwide Mobile Phone Sales Grew 35 Percent in Third Quarter 2010; Smartphone Sales Increased 96 Percent,” Gartner Newsroom press release dated November 10, 2010 and available online here.
Original source: Gartner Inc.