The six-part show – entitled Harry & Meghan – was unveiled in December, with the first three episodes released first and the others following later.
It saw the couple giving people a peek at their lives, including the story of how they first got together and the difficulties they said they faced. It also included a series of explosive claims.
The streaming service has now reported its fourth quarter earnings and disclosed a gain of 7.7 million subscribers during the October-December period, a stretch that included the debut of an ad-supported option for seven dollars (£5.65) per month.
Both Buckingham and Kensington Palace have remained silent over Harry’s allegations in the series that the Prince of Wales left his brother terrified after screaming and shouting at him during the Sandringham summit.
Harry also claimed in the show that Kensington Palace “lied to protect my brother” when it issued a statement denying a story William had bullied him out of the royal family.
And he accused Charles of lying at the tense Megxit crisis meeting with the Queen in January 2020.
The show was released in the run-up to the publication of Harry's book, Spare, in which he further talks about his life behind the scenes.
The controversial memoir has become the fastest-selling non-fiction book in the UK since records began in 1998.
Additional reporting from PA.
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