I think when the whole amazon aws-sdk is available in fusetools will give us the possibility to build applications to store and retrieve data for thousands of users at the same time and scale to many more for a reasonable price.
Any hint how to do this example with fusetools http://docs.aws.amazon.com/amazondynamodb/latest/gettingstartedguide/GettingStarted.Js.01.html
Best regards.