We've been doing it for a long time. It's called some reliable servers in multiple locations with copies of the same data plus some offline backups (esp tape). There's many non-technical, Fortune 500 companies whose data has lasted longer than Amazon's existence. Cheapest version of this involves two high-capacity boxes at two locations each with maybe a colo agreement. Let's you keep replacing stuff as servers and drives fail. I've even done it with embedded boxes (VIA Artigo's) in the past where data volume wasn't high.