"At the very least, I think you’ll come to agree with these takeaways:
The paid-up-front app market is smaller than it may appear.
Coverage from influential bloggers can drive more sales than an App Store feature.
Paid-up-front business models don’t generate sustainable revenues.
If you want to make “real money” from a paid-up-front app, your launch week has to be be a box-office smash.
Don’t launch your paid-up-front app at a reduced price. Demand for your app will likely never be higher again. Price it accordingly.
Sustainable revenue must come from other sources than the original app purchase, either from consumable in-app purchases, or from recurring subscriptions."