slowly reducing the price doesn't work because the consumer would see that the price is being reduced, and wait for the reduction to stop, even if the current price would've been worth it for the consumer to purchase (aka, they would've gotten excess value at a higher price, but still wait for the reduction to finish). After all, buying the app isn't urgent.

So therefore, a different way to discern the price sensitivity is needed. Often you will have to have a discount deal that is time limited, and may be targeted geographically.