Google Home’s biggest challenge will be handling accounts for the whole family

I have an Amazon Echo at home, and it's the one high-tech gadget my wife and I share. We often take turns asking it questions and giving it commands during a busy breakfast. There isn't anything particularly personal about the way we interact with Amazon that makes this a struggle, but the device can only be linked to a single account when connecting to something like Google Calendar or Spotify. This can be a pain point when, for example, my wife wants to ask for a Spotify playlist for her accou