This is a good list. Point 3 alone would net a lot of customers alone, be it banking or other. A lot of people, in the tens to hundreds of millions, not throu

This is a good list. Point 3 alone would net a lot of customers alone, be it banking or other. A lot of people, in the tens to hundreds of millions, not through choice of not wanting to use Google Play Services (or knowing what it is) cannot access Play Services on their locally purchased / locked device. These people are largely outside North America / Western Europe, potential customers for whom a service such as that of OP may be very attractive.