Should I charge for an iPhone app, or use ads?

It turns out that if you want to make money then yes. The CPM (cost per thousand ad impressions) on an iPhone app is so low that you're better of charging.  Do the ads networks really value mobile app inventory at the same rate as websites?  Or is this a bit of cream for the networks advertisers at this early stage of the app environment?  Of course if you're a brand wanting to connect with your customers there's no doubt that you shouldn't charge.  However this presentation above should help to show that you'll get most of the use of the app in the first day,so make it compelling.