Kanye West: Album Sales Saving Tidal ... Membership Doubles

Kanye West just did Jay Z a HUGE favor -- his new album put Tidal back in the game by giving the music service a huge financial shot in the arm.

Sources connected to Tidal tell TMZ ... "The Life of Pablo" and its debut at MSG has already been streamed millions of times in less than two weeks, which is a record for the service. We're also told subscribers to the app have more than doubled from around 1 million to 2.5 million.

In fact, we're told the album's been so successful his team is discussing plans for another release, which may include a physical copy.

Tidal reps have been tight lipped about numbers, but they've gotta be happy with this: The new subscribers could eventually add up to at least $15 mil in additional revenue.

Not a bad feather in Yeezy's cap.