I really like how most applications in the iOS store have been about upgrades. When a new version comes out I get it automatically without paying. Camera+ is a great example.
Because the user base for the platform has been growing the potential install base for your application grows with it. The graph in Wil's post shows that the same application had a huge sales surge just because more people were exposed to it.
If a new version of Delicious Library comes out his existing customers will be very happy with the new features and bring more customers in with them. I bet Apple would even promote the new app and a huge sales spike would happen again.
In my mind the new model isn't how to get the most money from your customers, it's getting the most customers.
I find the current 'goat users into paying X/per year to keep things current' model so distasteful that I will seek any and all possible alternatives before I consider buying any app. I tend to think developers would sell a lot more if people only had to pay once... but who knows.
Because the user base for the platform has been growing the potential install base for your application grows with it. The graph in Wil's post shows that the same application had a huge sales surge just because more people were exposed to it.
If a new version of Delicious Library comes out his existing customers will be very happy with the new features and bring more customers in with them. I bet Apple would even promote the new app and a huge sales spike would happen again.
In my mind the new model isn't how to get the most money from your customers, it's getting the most customers.