The only way Amazon would accept BTC would be to exchange it to FIAT immediately, these big organisations are not interested in Bitcoin or other coins mass global adoption (yet), but as a form or redeemable payment, then quite possibly yes - but what it would take to persuade these guys, who knows. Oh, and Steam accepting BTC? They do not hold the coin but instead exchange it for FIAT as above. Maybe this is because of the volatile market so as a fear of losing funds, or maybe a deeper esoteric reasoning... #BankingSystem