And how do they achieve it? Where do they even start?

We have two apps that have had nearly 4 million downloads across both app stores. Here's been the growth of our Mac app, for example: http://qbix.com/calendar . Our average reviews are very close to 5 stars out of 5 after thousands of reviews.

It's all organic. People just found us in the store. We were never contacted by Apple to get featured, and we had no way of contacting them, that we knew of. So I'm curious. It's not just about numbers.