Direct TV Now is a streaming service from AT&T that offers live TV programming over the Internet. It gives you access to over 60 live channels for $35 per month. This includes popular stations, such as CNN, the Hallmark Channel, ESPN, the Disney Channel, HGTV, TBS, Discovery, Bravo, Animal Planet and Bloomberg, among many others. But you can also choose to add HBO, Starz or Showtime for an extra $5 to $8 per month.
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.