For a productivity app I have seen night and day difference in earnings between "paid upfront" and "free with iap". I started with the paid model and switched t

For a productivity app I have seen night and day difference in earnings between "paid upfront" and "free with iap". I started with the paid model and switched to freemium. In the months after the initial boost due to "apps gone free" scrapper sites I got as many iap sales in a month that I had accumulated in two years while the app was paid. Paid upfront model is dead on iOS, unless you are some big shot company that will have their application featured on day 1.