There's no secret here with Bitconnect making massive payouts and how they can do it. No one buys BCC and holds them. They buy them and "lend" it back to them. They control their own exchange with little volume. They control almost all the BCC coins. If you check the VOLUME history, you see giant spikes of which no one can trade that many coins since no one owns or controls any BCC. If they control the exchange and control the coins, they control their price and control the market cap. There's no value in this business.
Is it a scam? Well, almost every coin or token on the market has no intrinsic value. It is a very dishonest business.
What will happen in the long run? We'll if Bitconnect can't sell their BCC coins it will be a collapse when enough users cash out.