Why do people pay for it?

The application, "Where To?" published by taptaptap, is selling on AppStore.

From 7/11 to 8/2, it's been sold 24,094 pieces by costing USD$2.99.

I'm not excited when I know the functionality of this application. The same functions is already on the most of GPS Handheld device.

So, why do people pay for it? Because of lots of iPhone in market? Because of Apple's type?

If I design an App on WM, can I earn that much?