I changed pricing from a fixed upfront price to In App Purchases which lets customers download and evaluate the App for free.
I'm now much more confident that only people who actually like the app will pay money. Whereas before, some of the customers might have been disappointed after paying and downloading the app because they were not sure what they will actually get.
For now there are two subscriptions. A monthly and a yearly subscription. Each subscription starts with a discounted first period. And the yearly subscription costs less than the monthly subscription for the same period.