Bitcoin is the opposite of a pyramid scheme from the point of view of Bitcoin miners. The Bitcoin protocol is designed like a cannibalistic arms race. Every additional miner prompts the protocol to increase the difficulty of mining. From a social point of view, Bitcoin is a pure market. The price of Bitcoins fluctuates based on market supply, demand, and perceived value.
Its the same term which was used by the Russian president putin to accuse bitcoin.But whoever term it,its completely wrong.Here there is no need for anyone who has bitcoins to promote others to buy bitcoins to increase his income.Rather he could just hold his bitcoins and enjoy the price rise.