Just when traditional pay-TV providers thought it was safe to lift the covers and get out of bed, cord-cutting has reared its ugly head again.

In the fourth quarter, pay-TV cord-cutting suddenly took off again in the US as more consumers flocked to the new breed of OTT video "skinny bundle" packages. The US pay-TV industry shed an estimated 319,000 video subscribers in the fall quarter, a stark reversal of its 48,000-subs gain in the year-earlier period, according to the latest figures compiled by MoffettNathanson LLC . Craig Moffett, a principal and senior analyst at MoffettNathanson, noted in his report that the rate of acceleration -- 40 basis points -- was "the largest on record for a single quarter."

Moreover, pay-TV providers lost 1.7 million video customers over the full year of 2016, a hefty increase over their loss of 1.1 million subs in 2015, MoffettNathanson reports. This yearly loss, which amounts to 1.7% of the pay-TV subscriber base, is also the biggest one yet for the industry.

Of course, as my colleague Adi Kishore rightly points out in our sister publication Telco Transformation, the mighty US pay-TV industry still has a very impressive 96.5 million subscribers. So it's not exactly disappearing any time soon. But change is afoot and cord-cutting is clearly having a greater impact. (See Tough Week for Traditional TV and Will 2017 Be Cord-Cutting's Big Year? )

In fact, in his exhaustive report on the subject, Moffett contends that cord-cutting may be even higher than it first appears. Citing the latest US Census Bureau stats, he notes that Americans formed 800,000 new homes last year, up from about 500,000 in 2015. Given that the national pay-TV penetration rate is 81%, this should have led to about 650,000 new pay-TV households. Yet the industry instead lost 1.7 million subscribers, indicating that "there were closer to 2.5 million lost or missing pay-TV subscribers in 2016," he wrote.

Moffett attributes much, if not all, of the accelerated pay-TV subscriber losses in Q4 to new OTT skinny bundle players like AT&T Inc. (NYSE: T)'s DirecTV Now, which launched at the end of November and made a strong debut despite a rash of service problems and customer complaints. Based on the latest data from AT&T, Moffett figures that the 100-channel DirecTV service signed up about 230,000 subscribers in its first month alone.

"It is hard not to credit the acceleration in cord-cutting in Q4 to DirecTV Now, which arrived on the scene in late November," Moffett wrote. "And it is not hard to pin DirecTV Now's success on its super-low promotional price of just $35… As we've always noted, price is everything and DirecTV Now's initial promotional price was very, very low."

Between them, Moffett estimates that Dish Network LLC (Nasdaq: DISH)'s Sling TV service and DirecTV Now, two of the leading OTT skinny bundle products in the market, netted 900,000 subscribers last year. No estimates are available for the third leading skinny bundle service, Sony Corp. (NYSE: SNE)'s PlayStation Vue.

Want to learn more about the latest pay-TV market trends? Sign up now for Light Reading's Cable Next-Gen Technologies & Strategies event on March 21-22, at the Curtis Hotel in downtown Denver.

Now, with Google (Nasdaq: GOOG) prepping to enter the skinny bundle market with YouTube TV, the big question is how much impact the new YouTube entry will have on both the pay-TV market and its skinny bundle rivals. Unlike the larger DirecTV Now service, which has since jettisoned its initial promotional price, the new 40-channel YouTube entry appears set to retail at $35 a month for at least the first few months. (See Will YouTube TV Hit OTT Sweet Spot?)

"Now YouTube will compete at the same price point" as DirecTV Now's promotional price, Moffett notes. "And YouTube will be followed by Hulu, which is expected to launch sometime in the next few months. They may have no choice but to compete at the same low price."

— Alan Breznick, Cable/Video Practice Leader, Light Reading