Exchanges happen almost instantly because Changelly never actually controls your tokens but just exchanges them. Changelly works in nearly every country but you will need another cryptocurrency in order to purchase bitcoins. The best part: No fees! Low-liquidity exchanges experience similar problems, with price slippage representing a major potential cost. Paper wallets allow you to print out your Bitcoin public and private keys and use this piece of paper as your wallet. BTC search volumes: Indicators of Bitcoin mainstream acceptance?