It’s hard to compete in the streaming music world unless you have a family plan, and Amazon knows it. The shopping pioneer has introduced a family plan for Amazon Music Unlimited that lets as many as six people listen to tunes for a low price. If you’re not a Prime subscriber, the pricing is a very run-of-the-mill $15 per month. You won’t save anything by leaving Apple, Google or Spotify. However, it’s another story for Prime subscribers — you have an additional option to subscribe for $149 per year, or $30 less than what everyone else pays. If you’re already devoted to Amazon and don’t care for rivals’ exclusives or features, this may be your obvious choice.