Bitcoin (BTC) turned out to be a far more attractive prize than airline miles or other cashback rewards, new data from BlockFi suggests.  It’s been three months since the New York-based crypto loans startup launched its Visa-backed Bitcoin rewards credit cards, BlockFi Rewards Visa Signature Credit Card, to customers. The card offers rewards in Bitcoin instead of using a more traditional points system. According to the company, if the average Bitcoin rewards card owner continues the shopping habit seen in these first three months, they'll be on track to spend more than $30,000 per year on average. This is almost six times the average of $5,111 per cardholder in the United States.