Earlier this year, I expressed skepticism that the iPhone would be able to break the convergence rule: historically, consumers have preferred devices that do one thing well over devices that combine multiple equally important functions. (The big exception being the personal computer.)
Some figures released today by retail researcher NPD suggest I may be wrong. Of the 38 million phones shipped to U.S. consumers last quarter, 50% of them were able to play music. That's up from 25% in the previous year.
Doing some quick math, it appears that the iPhone made up about 6% of all music-capable phones sold in the U.S. during that quarter. That's not a huge number, but there's probably some halo effect. That is, some people may not have wanted to pay iPhone prices, or were unable or unwilling to switch their coverage to AT&T Wireless, but wanted a phone that could play music nonetheless.
I suspect that part of the sales growth in this category is driven by the simple fact that multifunction phones are getting cheaper, and people will always tend to buy the most phone for their money. Moreover, the carriers are promoting music-capable phones because it helps them sell additional services. So are people actually using their phones to play music?
Based on the most recent data I can find on this subject, they are indeed. According to a Mar. 2007 study by M:Metrics, 31% of users with both types of devices (music-capable phone and portable music player) are using the phone as their primary music player, and 11% of that audience are using both equally. This was before the release of the iPhone, so no doubt that percentage has gotten even higher.