On launching: scale through referrals

As long as the notion of exclusivity is there, you have a club with members, and members of an exclusive club like to show off, and be very cool that they can get you in. So offer that functionality: let current members invite new members.

This will give you a very cheap and easy lead generation channel, but this only works and will only happen when the original members feel that this is so cool and useful that they want to get their friends also on it.

If the above doesn’t happen enough ‘for free’ because of its coolness, you can also experiment with other incentives: get free coins/minutes/GBs for you and your friend if you refer a friend and that friend signs up (and pays of course).