WARNING: iPhone Sales Ranking in Mirror May Be Smaller Than It Appears

Get this: Apple’s (AAPL) iPhone 3G is now the second best-selling mobile handset in the U.S, after Motorola’s (MOT) RAZR V3. According to NPD Group, the device outsold the BlackBerry Curve, BlackBerry Pearl and Palm (PALM) Centro between June and August to claim about 17 percent of the U.S. smartphone market. Moreover, about 30 percent of stateside customers who purchased an iPhone 3G during that period switched mobile carriers to do so. Nearly half, 47 percent, switched from Verizon (VZ) Wireless, another 24 percent switched from T-Mobile (DT), and 19 percent switched from Sprint (S).

An impressive showing. That said, NPD’s metrics don’t include corporate/enterprise mobile phone sales, which likely favor the Blackberry above all. Presumably, the iPhone’s ranking would have been quite a bit different if it did. Still, 17 percent of the U.S. smartphone market is quite an achievement.