Join Coinbase and get ~10 USD worth of Bitcoin (BTC) when you trade 100 USD worth of cryptocurrencies. That means either you deposit and trade cryptocurrencies or deposit money and buy cryptocurrencies with it.
Upon registration you will receive 0.05 Coins directly into your wallet. There is a hidden 5$ PayPal reward which will become visible upon earning 16 Coins on the site (unlockable only via referral links).