Hulu and YouTube both launched live streaming services last year to take on big cable companies with packages of online TV channels. It’s still early, but they’re making some progress, according to numbers revealed to CNBC.

Hulu’s live offering has about 450,000 paying subscribers, not including recent promotional customers, according to people familiar with the matter. YouTube Live has just over 300,000, said the sources, who asked not to be named because the numbers are private.

Neither Hulu or Google, which owns YouTube, have formally announced subscriber numbers, and representatives for both companies declined to comment for this story.

Over-the-top providers of live content are gauging how many American households have an appetite for live online video as an alternative to traditional cable packages. YouTube TV costs $35 a month, and Hulu with Live TV costs $39.99 per month, with both offering viewers a combination of live sports, news and events from a host of networks.

While they have a certain appeal to cord cutters, Hulu and YouTube may struggle to substantially grow their customer base because canceling is so easy and the value proposition compared to video on demand isn’t very good, said Rich Greenfield, an analyst at BTIG.

“If you don’t care about live sports, the original Hulu product is awesome,” Greenfield said. “You can get all of the programming you want for more than $30 less. And YouTube is free. It actually shows you how poor the value proportion is for live TV.”

Hulu Plus, which competes with Netflix and Amazon Prime Video, costs $8 a month for an online library of TV shows and movies. Hulu announced earlier this month that it has more than 17 million paying customers spread across both its on-demand and live TV services.

The live services from Hulu and YouTube trail DirecTV Now, which said last month it had reached 1 million subscribers, and Dish Sling, which research firm comScore estimates has more than 2 million.

DirecTV and Dish have been willing to give viewers an alternative to their legacy services to compete for a younger audience that can buy video content without the cost of installing of a satellite dish.

YouTube TV launched in April and is available in over 80 percent of U.S. households. Hulu started offering the beta version of its live service the following month with 50 channels.

Over the last several years, online live TV services have hammered out programming agreements with cable channels and broadcast networks to bundle programming that competes with traditional cable-TV operators, such as Comcast and Charter.

But cable and satellite TV are stickier businesses than web-based services because they’re so difficult to cancel, Greenfield said.

“You can cancel these live streaming services with four clicks of a button,” Greenfield said. “Have you tried canceling your cable?”

Disclosure: Comcast is the owner of NBCUniversal, parent company of CNBC and CNBC.com.