This is interesting: the prevailing argument about App Store pricing seems to be that developers are rushing down to 99 cents because apps priced there sell better (and developers say they can't fund really great apps priced there). But Mobile Orchard did a little number crunching, and their conclusion upends the whole premise: 99 cent apps don't sell any better than their more expensive counterparts. They plotted each app's popularity against its price, and while there are a few 99 cent apps out there selling better than any higher-priced app, the only real way to make the app "sell" better is to give it away for free. Above $0, price doesn't really matter than much in terms of popularity.
You could argue that Apple's 0 to 1 popularity scale doesn't tell us much (we're not looking at actual sales here, just a number Apple has given to each app in terms of downloads), but Mobile Orchard's conclusion makes sense, in a strange way: free apps, we know, are much more popular than any paid apps, and if people are willing to pay 99 cents, why wouldn't they be willing to pay more? Why should a 99 cent app sell better than an app of equal usability that costs $1.99? It shouldn't, and according to this data, it doesn't.
Very interesting. There is an exception -- in the Entertainment category, 99 cent apps do sell markedly better than the apps above them (Games, also, as you can see above, seem a little stronger in the 99 cent bar). But in the Business and Productivity categories, higher-priced apps actually sell better than their cheaper counterparts. People will pay what your app is worth, whether that's $1, $10, or even higher. The problem may be getting people to understand the app's worth in the first place (and that's where something like an App Store trial system might work), but Mobile Orchard's data says that price isn't a factor in an app's sales.