In today’s Circuits column, tech columnist David Pogue asks an important question about the $5 billion ringtone industry for mobile phones: why does it exist at all? Apple’s latest moneymaker for itself and the labels is the ability for you to re-purchase certain songs you’ve already purchased, so that you can load them onto your phone as ringtones. But before you marvel at Apple’s chutzpah, they’re actually charging less per ringtone than major carriers like T-Mobile, Sprint, or Verizon.
