Confession 1: Soon as the App Store opened, I started downloading. Free apps mainly, but I bought more than I thought I would as well.

Confession 2: I don't use most of them regularly. I mean, I use the built-in apps all the time, daily if not near-constantly in the case of Phone, Mail, and Safari. But the App Store stuff? Eh.... A couple have become regulars but most are occasional at best and some I no longer even bother to store on the iPhone (i.e. they've been relegated to iTunes purgatory.)

60 million downloads, 30 million in sales, and Steve Jobs thinks it could be a billion dollar business. So somebody must be using them, right?

Om Malik consulted Greg Yardley of Pinch Media (which tracks user behavior and provides statics based on that behavior for iPhone Apps) who says that, based on their sampling (which they themselves say currently consists of only a few developers), less than 20% of users return to an App at least once a day, and of them, the average time spent on an App is 5 minutes.

By way of contrast, however, Casey already posted some pretty staggering numbers from the big players like Facebook and Loopt who are seeing tons of usage.

UPDATE: Greg Yardley, in the comments below, points out that Facebook numbers are not necessarily inconsistent with Pinch Media's.

Hmmm... Could it be that the App Store is still in its honeymoon, right smack in the middle of a little developer gold rush, where for every Apple Remote there's a dozen (okay, 3 dozen) "I am Rich" / Flashlight applications? Since there's no demo or beta, its easy to download free apps and moderately easy to take risks on under $10 apps, and come up less than thrilled.

All usage numbers tell us for now is that there aren't -- yet -- enough really killer apps, but at the same time so many developers and companies are becoming involved, the odds of another -- and another -- killer app coming are getting better and better.

So, no I'm not using my iPhone Apps a lot, but I expect better apps to come along that demand I use them a lot more.