I just read and interesting article in this site, there you will see that one of the facts they expose is that 59% of the developers don’t break even. From my experience and the people I know I totally relate to this. Two years ago things were different, by just launching an app thousands of people would download it and see if it was of any interest, by then good quality was key to retain them. Today good quality is not enough; you also need to have an appealing design for the segment you are targeting as well as a good marketing strategy around it. Only a few exceptions get on the exponential curve of the popular apps in iOS, the rest need to work hard for it.