I think minute incremental charges are the signature for a service that is "serverless". While serverless components are part of your architecture, what is exposed and billed monthly is a standard SaaS interface. In this sense, it is only utilized for its buzzwordiness.
That nitpick aside, this looks pretty neat.
I do think though, that there is value in talking about new kinds of software architecture is enabled by serverless infrastructure. I wrote up a post on how we at Graphcool use serverless functions internally and what we are planning to integrate in the platform in the future: https://www.graph.cool/docs/blog/introducing-the-serverless-...