These are: New York, San Francisco, Los Angeles, Chicago and Philadelphia.
It gives viewers access to over 40 channels, plus the ability to store unlimited video content in the cloud. (Though shows will only be stored for a limited time.)
You also get access to everything on YouTube, including the paid-for YouTube Red videos. That means you can watch a show or film, then check out some video reviews of it on YouTube, to see what other people had to say. And all from the same service.
Strangely, you can only access it on a phone at the moment, though you can beam it to your telly using a Chromecast streaming dongle. We presume Google will bring YouTube TV to smart TV platforms soon.
A subscription costs $35 (£28) a month, and can be shared with friends and family. Like a SIM-only deal, it's a 30-day rolling contract, so you can cancel at any time and not face any hefty leaving fees.
Hopefully the service will come to the UK soon. We'll keep you posted.