Although Apple just recently announced more than 15 billion application downloads from the iOS App Store, Asymco has reason to believe that app downloads have overtaken iTunes music purchases.

“It was only a few weeks ago (at WWDC) that we had an update on the app store growth rates. The data was presented here. One of the data points from the event was that iTunes hit 15 billion song downloads. Last week we heard that iTunes also hit 15 billion app downloads. The milestones were reached within less than a month so it’s a fairly safe assumption that apps have overtaken songs.”

Asymco claims that more than 31 million iPhone, iPad, and iPod Touch applications are downloaded each month – more than one million a day.  In comparison, the research group has concluded approximately 11 million tunes are downloaded on a monthly basis.

“The app download rate is now at least 31 million per month while the song download rate is about 12 million per month. Including books (but excluding video content), the App Store in now delivering at least 44 million new content downloads per month.”

The App Store has certainly showcased continual, consistent improvement — and Apple’s market shows no sign of slowing anytime soon.