They don't unless you have a good contract with them and even then it's dependent on zones and package size.
Fun fact: USPS acknowledges that our US territories are domestic while UPS and FedEx treat them as international. So its a little more of a chore and cost to ship to Puerto Rico and the like through anyone but USPS from the 50 states.
Ya know what's crazy? I got a Steam link when it became available and it barely worked because my computer and router sucked more than I realized at the time. Then last year someone made a video about it and said how awesome it was and I remembered I had it and plugged it in.
They were right! It still works great, and since I've upgraded everything since then, I now know my computer was the bottleneck back then. I'm curious what new features a new Steam link could add to make it worth a whole new device at this point.