Sounded to me it's more like they're using CDNs for content distribution and Amazon AWS for bulk/batch processing jobs. From the original article:
RLB: Could you describe at a high level what Netflix is doing on AWS?
AC: Encoding movies for streaming, log analysis, production web site and API, most everything that scales with customers and streaming usage. Easier to say what we don’t have there: most internal IT that scales with employee count, legacy stuff, DVD shipping systems, account sign-up and billing systems. We use Akamai, Limelight and Level3 CDN’s for streaming the movies, which is a cloud based service. There is an AWS CDN service, but they aren’t a big enough player in this space at this point.
RLB: Could you describe at a high level what Netflix is doing on AWS?
AC: Encoding movies for streaming, log analysis, production web site and API, most everything that scales with customers and streaming usage. Easier to say what we don’t have there: most internal IT that scales with employee count, legacy stuff, DVD shipping systems, account sign-up and billing systems. We use Akamai, Limelight and Level3 CDN’s for streaming the movies, which is a cloud based service. There is an AWS CDN service, but they aren’t a big enough player in this space at this point.