Game of Thrones' fourth-season premiere drew 6.6 million viewers on Sunday night, the network's largest audience since the Sopranos series finale in 2007.
Those are huge numbers compared to season three premiere, which drew 4.4 million viewers, proving that the show's audience is growing.
The ratings also help justify Game of Thrones' mind-boggling production costs. Its actors film on location in three countries, and its first season cost $60 million.
Despite Sunday night's success, the network does have to work on technical issues with its online-streaming service, HBO Go, which had trouble handling the number of people trying to stream the premiere at the same time.
HBO Go crashed for two hours during the 9 p.m. telecast, just as it did during the True Detective finale last month.
"HBO Go did experience issues due to overwhelming demand around the premiere of Game of Thrones," the network said during the telecast. "The service has returned to several platforms and we are working hard towards full recovery, which we expect soon."
Looks like there's trouble in the realm. Apologies for the inconvenience. We'll be providing updates, so please stay tuned. #GameofThrones— HBO GO (@HBOGO) April 7, 2014
You had one job, HBO Go...— MG Siegler (@parislemon) April 7, 2014
[Entertainment Weekly, NY Times]