Amazon’s return on its multi-billion-dollar investment in video programming, long shrouded in mystery because the company has declined to break out specific numbers, has been illuminated somewhat by internal documents obtained by Reuters.

The wire service said Amazon’s 19 original series as well as acquired series and films drew a total U.S. audience of 26 million as of 2017. Estimates by outside analysts have put total membership in Prime — the offering that bundles together streaming video with free shipping and other benefits — at 79 million, meaning roughly one-third of overall Prime members are active video consumers.

Amazon

Amazon has never publicly confirmed any Prime figures, though CEO Jeff Bezos says the company is committed to the strategy of pairing video with other goods because attention for video offerings entices customers to shop more. Also, he has said, regular video consumers renew memberships and convert from free trials at higher rates than customers who do not stream video.

The Man in the High Castle, whose cost for production and marketing was put at $72 million, drew 8 million viewers in early 2017, while also pulling in 1.15 million new subscribers worldwide. The acquisition cost for each subscriber, according to the documents, was $63.

Transparent, while a highly decorated critical favorite, has been on the wane, according to the documents. Its third season was drawing just 1.3 million viewers. It recently reached a creative crossroads when star Jeffrey Tambor exited the show amid sexual harassment allegations.

An analysis by J.P. Morgan estimated Amazon’s 2017 spending on original content at $4.5 billion. The Reuters report put it at $5 billion, according to company sources. Amazon has recently expressed a desire to spend what it takes to produce an equivalent to HBO’s Game of Thrones — a large-scale spectacle that drives subscriptions. It has ditched many smaller-scale shows, which were pointing in a different strategic direction. One such attempt is the pricey adaptation of The Lord of The Rings, which is reported to carry a price tag north of $200 million.

Amazon did not immediately respond to Deadline’s request for comment on the Reuters report.