Is it just mutual assistance or will it be possible to order such a service through the platform? Is cryptocurrency mandatory?
The main idea is mutual assistance. But if you collect many SNS coins - of course you'll be able to order any service from users, who want to earn... The main idea is that it shouldn't violate the terms of social network you use. Or you will be banned... And it's a question of cooperation with the social network administration.
The cryptocurrency will be mandatory. Using own cryptocurrency let's be independent from financial organizations and taxes. When you earn our tokens - you don't earn money - just any "bonus assets".
But! You still can exchange these "bonuses" into real currency. Outside our system, on any exchange, where we will be listed.
