“Lost in Space,” one of Netflix’s newest high-profile original series, drew 6.3 million U.S. viewers within the first three days of its release earlier this month, according to Nielsen.

In addition, in the first 72 hours of release (April 13-15) of all 10 episodes, “Lost in Space” viewers on average watched 2.6 episodes, per Nielsen. The media-measurement firm found the series was heavily binged — with almost 1.2 million people having watched the series’ final episode within those three days.

By comparison, the “Stranger Things” season 2 premiere episode average 15.8 million viewers from Oct. 27-29, while 11 million U.S. viewers who watched Netflix’s “Bright” during its first three days of release, according to Nielsen.

Famously, Netflix doesn’t release viewing metrics, holding such data close to its vest — leaving third parties like Nielsen to try to estimate demand. Netflix has pointed out that Nielsen’s estimates cover only the U.S. and only tracks viewership on connected TVs (excluding mobile devices and computers). The Nielsen SVOD Content Ratings, launched last fall, extrapolate viewership using audio-recognition technology that “listens” to what viewers are watching on TV.

In terms of Netflix premiere-day viewing, “Lost in Space” garnered 3.16 million viewers overall on April 13, according to Nielsen’s estimates. That puts it behind “Stranger Things” season 2, with 8.97 million on Oct. 27, and “Bright,” the fantasy cop movie starring Will Smith, which pulled in 5.35 million on Dec. 22. “Lost in Space” was ahead of “Marvel’s The Defenders” (2.8 million on Aug. 18), “Black Mirror” season 4 (2.1 million), and “House of Cards” season 5 (2.0 million on May 30).

Nielsen also found that the initial viewers of “Lost in Space” were 60% male and 40% female. Some other Netflix shows skew female, like “Fuller House” (67% female) and “The Crown” (65% female).

In “Lost in Space,” which Netflix has been marketing heavily, Will Robinson and the Robot form an unexpected, unbreakable bond that could mean the difference between life and death for the Robinsons.

The series stars Toby Stepehens (“Black Sails,” “Die Another Day”) as John Robinson, and Molly Parker (“House of Cards,” “Deadwood”) as Maureen Robinson, the family’s parental leaders. The Robinson kids are portrayed by Taylor Russell (“Falling Skies”) as Judy, Mina Sundwall (“Maggie’s Plan”) as Penny, and Max Jenkins (“Sense8,” “Betrayal”) as the curious and sensitive Will Robinson.

The series is produced by Legendary Television and written by Matt Sazama and Burk Sharpless (“Dracula Untold,” “Last Witch Hunter”). Zack Estrin (“Prison Break”) serves as showrunner. The three are executive producers alongside Synthesis Entertainment’s Kevin Burns and Jon Jashni with Applebox’s Neil Marshall and Marc Helwig.

The original “Lost in Space,” created by Irwin Allen, aired for three seasons, from 1965 to 1968 on CBS. The original also spawned a 1998 feature film starring William Hurt, Gary Oldman, Matt LeBlanc, Heather Graham and Mimi Rogers.