Just added a paragraph to the article that covers that:

> For the uninitiated, DVM stands for "data vending machines". They're actually sort of hard to describe — in technical terms they act more like clients, since they simply read events from and publish events to relays. In most cases though, these events are part of a request/response flow initiated by users elsewhere on the network. In practice, DVMs are bots, but there's also nothing to prevent the work they do from being powered by human interaction. They're an amazingly flexible tool for building anything from custom feeds, to transcription services, to chatbots, to protocol gateways.