Google Chromecast. The Chromecast device differs in that you plug the dongle into the HDMI port of your TV and "cast" the screen on your phone or tablet to your TV. This means that your phone acts as the remote for the Chromecast, which makes it a little more difficult to use that other dongles. Still, the overall idea of using internet television content and placing it on your television to watch on a large screen is at play.
ISP’s vary by location. I’m maintaining a list of providers with affordable internet only plans you can use to cut the cord. If you can’t find one on that page, try your existing provider. Now I know the “big” internet providers seem only to offer “triple play” packages bundling phone, TV, and internet. However, if you dig around on their site you should be able to find an internet service offering.
PlayStation Vue streams with 720p resolution. I use an Amazon Fire TV, but with an Ethernet connection to get a nice picture. Right now, if you look at PS Vue, Sling TV and DirecTV Now and fuboTV, they all stream at about the same quality. I can tell you that when I have family or friends over, they think the TV is showing cable. (I don’t have a 4K TV.) Check out a video of my TV streaming PS Vue on Amazon Fire TV: https://www.youtube.com/watch?v=RabL1GGhA6Y
It’s a critical issue since Sling TV had more than 2.3 million subscribers as of the most recent quarter while DirecTV Now serves more than 1.8 million clients. AT&T recently launched an even skinnier bundle called AT&T Watch that appeals to viewers not interested in sports. Other companies including Verizon and T-Mobile may get into the skinny bundle business, which UBS expects to represent 25% of all pay-TV subscriptions by 2022.
The question of "when does it make sense?" can easily be rephrased as "how much money can I save?" and one of the biggest factors will be the price difference between combined internet and TV service or just internet. These are also the options that vary the most widely based on where you live, and the availability of promotions or contracts that can keep prices down for a short time.