NPD is getting a lot of media attention this morning after claiming that Android gadgets are now outselling the iPhone in the U.S., but the news shouldn’t be so surprising. Apple’s iconic handset is available only through AT&T, of course, while Android now distributes phones through every major U.S. carrier. And I think Android is just as attractive as Apple thanks to a number of top-notch handsets and an app store that offers plenty of great titles. But the number one reason Android’s momentum in the U.S. continues to grow is the fact that it enjoys substantial carrier marketing — particularly through Verizon Wireless, the nation’s largest operator. Which is the umpteenth piece of evidence that no matter how good a handset is, it won’t sell unless someone backs it with some big-budget marketing muscle.