People who pooh-pooh the cord-cutting phenomenon love to argue that the cost of streaming services such as Netflix and Hulu really adds up , to the point where someone who dumps cable in favor of streaming isn’t actually saving money.

Such skeptics haven’t accounted for free streaming services like Tubi, which allow cord cutters to watch thousands of movies and shows without subscriptions. Although Tubi’s been around for almost five years, it’s enjoying a growth spurt as more people ditch cable and seek cheaper alternatives. The company just announced that viewership in 2018 was 4.3 times greater than the year before, and that December alone brought in more viewing time than all of 2017. (It did not share specific hard numbers, though it claims to be the largest ad-supported streaming service.)

The rest of the industry is now taking notice of free streaming, especially with the subscription business becoming more crowded. Last week, Viacom acquired Pluto TV for $340 million to jump-start its ad-supported video business, and earlier this month, mega-broadcaster Sinclair launched a free streaming service called Stirr. Amazon also launched a service called Freedive through its iMDb brand, and The Roku Channel has been expanding its ad-supported videos beyond Roku smart TVs and streaming players to web browsers, mobile devices, and Samsung TVs. Even Comcast recently announced plans for a free streaming service–albeit just for existing pay TV subscribers–in 2020.

In the age of cord-cutting, the reality is not that people will subscribe to a dozen streaming services and fail to save money. What they’ll actually do is pick a few subscriptions–as surveys from TiVo and Deloitte have estimated–and pad them out with free services like Tubi.

“I think what everybody has finally come to realize is that the SVOD market is saturating,” says Tubi CEO Farhad Massoudi, referring to subscription-based streaming services such as Netflix. “There isn’t room for too many SVOD services on an average household basis, and that means [ad-supported streaming] … is the next big frontier.”

Streaming the 99%

The most obvious reason for the rise of ad-supported streaming is the sheer number of subscription services competing for space on customers’ TV bills. Beyond Netflix, Hulu, and Amazon Prime, there are premium cable-based channels such as HBO, Showtime, and Starz, plus CBS’s All Access service and even full-blown live TV bundles like Sling TV and YouTube TV. New on-demand services from Disney, AT&T’s WarnerMedia, and (it seems likely) Apple will also enter the fray later this year, and niche services such as CuriosityStream (for science documentaries) and Acorn TV (for British programming) are available by the dozen. It’s safe to assume not all of these services will succeed.

Still, subscription overload alone doesn’t explain the sudden rise of ad-supported streaming.