Clarifying Internal-only

There is a lot of positive feedback about the Dynamo paper but I noticed that something I wrote in introducing the paper is being misunderstood. This was my fault, I wrote it too strongly.

What I meant by internal-only is that Dynamo is not directly exposed externally. However, Dynamo and similar Amazon technologies are used to power parts of our Amazon Web Services, such as S3. We are using these kinds of technologies to constantly improve the services we offer.