HBO Now, the streaming service, has about 800,000 paying subscribers.
Until now, customer numbers had been something of a secret because many of the people who signed up for the service, which launched last April, took advantage of free promotional offers.
HBO Chief Executive Richard Plepler announced the subscriber count Wednesday during a conference call with Wall Street analysts to discuss Time Warner earnings.
"We see an enormous amount of opportunity ahead," Plepler said of the service, adding that the company was pleased with its Jon Stewart and Bill Simmons deals that should provide ongoing content and help HBO Now carve out a niche among streaming services.
But Wall Street analysts wondered whether that customer number was low, given the enormous popularity of Netflix, which has more than 40 million subscribers in the U.S. One analyst asked whether HBO was considering cutting its $14.99-a-month price for the service to make it more competitive with Netflix and Hulu.
"We don't have any plans to change the price point at this point," Plepler said, although he suggested the company might not be rigid on the price.
"We think our premium price makes sense, and we have no plans right now to change it," he said.
But the company plans to ramp up its promotion of the service after spending several months working out technological issues.
"We are going to market the service more aggressively," Plepler said. "HBO Now is an additive part of our growth strategy."
HBO gained more subscribers from its traditional business of selling linear premium pay-TV subscriptions with its longtime partners, the pay-TV operators. In 2015, HBO and Cinemax added 2.7 million domestic subscribers, including the subscribers who signed up for HBO Now.
Time Warner Chief Executive Jeff Bewkes on Wednesday declined to shed any light on the company's negotiations to take a 25% ownership stake in Hulu. That service is owned by NBCUniversal, 21st Century Fox and Walt Disney Co. Time Warner is interested in joining the group.
But Bewkes did say the company is pursuing other over-the-top opportunities, including some options with its Turner channels. In the last earnings call in November, Bewkes appeared to be rallying others in Hollywood to take on Netflix, which has grown in clout.
"We think it is a good thing that we have these new entrants offering more content on demand," Bewkes said.