Also, internet-only TV subscriptions are playing a small role. Leichtman reckons that there are 1.36 million Sling TV subscribers, and 375,000 DirecTV Now members.

The shift in power comes in part through Netflix's ever-greater reliance on originals. There's enough high-quality material that it can compete with more established networks. However, it's also getting a boost from the decline of conventional TV. Those traditional sources lost 760,000 subscribers in the first quarter of the year versus 120,000 a year earlier. Leichtman believes a combination of cord cutters and reduced marketing toward cost-conscious viewers is to blame. Cable giants might not be in dire straits, but they're clearly focusing on their most lucrative customers as others jump ship for the internet.