Buyer A uses BTC to buy Bitconnect Coin (BCC), which is traded almost exclusively on BCC's own exchange. Buyer B buys BCC and his money is used to pay Buyer A. Buyer C buys BCC and his money is used to pay Buyer B. When the supply of new investors eventually dries up, the whole thing will collapse and those at the end of the chain will be left with a worthless token. This is the very definition of a Ponzi/MLM scheme.