Boosted in part by an extensive free sampling campaign, time-travel drama “Outlander” has gotten off to an encouraging start for Starz — becoming the premium cabler’s most popular series premiere in its history when all multi-platform viewing is counted.

Nielsen estimates that more than 720,000 watched the series opener of “Outlander” on Saturday night, and a total of 2.3 million watched during its opening weekend on the Starz flagship channel alone. Roughly 51% of those adults watching were female, the network said.

Early reporting of the week-long on-demand, online platforms and affiliate TVE services yielded an additional 1.4 million to date, bringing the total to 3.7 million and counting.

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The previous high for Starz was the January premiere of “Black Sails, which drew 3.5 million multi-platform viewers for its premiere. That show drew more viewers in its regular-timeslot premiere (850,000), but television usage levels are much higher at that time of the year.

“Outlander” is based on the novels of the same name by Diana Gabaldon. It takes place in 1945, when World War II nurse Claire Randall finds herself transported back to 1743 Scotland.

Starz ordered a 16-episode first season of “Outlander.” It airs Saturdays at 9 p.m.

SEE ALSO: Starz’s ‘Outlander’ Woos Women with Strong Female Protagonist