Source: VICE Sports
As noted, VICE Sports has a new big story about NJPW star Kenny Omega. Omega's match with Kazuchika Okada at WrestleKingdom 11 was mentioned, and it was noted that NJPW added 10,000 new subscribers, with 5,500 coming from the U.S. prior to the event.
It was also mentioned in the article that Okada's NJPW contract last year was for $2.2 million / year. If that is accurate, that would be a significant amount of NJPW's annual revenue. Bushiroad founder Takaaki Kidani had noted in 2015 that while their revenues were increasing, NJPW's revenue for that year was $21.6 million U.S. (2.7 billion Yen).