HBO and Sky ponder how to fill Game of Thrones gap

The final episode of Game of Thrones has brought an end to one of the most ambitious and expensive television programmes in history while also posing a challenge for television executives trying to work out how to create a similar culture phenomenon in the future.

Related: Game of Thrones recap: season eight finale – The Iron Throne

Despite mixed reviews for the show’s eighth series, in which major storylines were wrapped up in a run of just six episodes interrupted by the occasional stray coffee cup, the programme has been a ratings success for US pay-TV channel HBO and UK broadcaster Sky.

Sky‘s paid-for streaming service Now TV has benefited from the Game of Thrones effect, but data from from ratings agency Barb suggests that the number of British households with a Now TV subscriptions has flatlined at about 1.6m at a time when Netflix is pushing ahead to market dominance with 12.3m households.

Enders Analysis warned that the expected Game of Thrones boost may last “only temporarily”, with Now TV customers tempted to unsubscribe now they are no longer being treated to new updates on the activities of the Stark and Lannister families.

The programme’s departure will also be felt keenly in Northern Ireland, where much of the show has been filmed, with the final series reportedly costing an average of $15m an episode.

HBO is also facing its own concerns over what comes next. The network is facing deep structural issues as the ability of traditional television companies to take big budget risks on new shows dwindles. The longevity of Game of Thrones means that the show has spanned an entire transformation in the way television is consumed, accompanied by a growing emphasis on a handful of major shows.

HBO has been toying with a number of spin-offs and sequels to fill the gap and sate demand from viewers. So far, only one pilot had been commissioned: a series written by British screenwriter Jane Goldman which covers events thousands of years before Game Of Thrones. The financial temptation of a swift return to Westeros could be hard to resist.

Programme creators David Benioff and Dan Weiss first pitched the show to HBO in 2006 at a time when YouTube was still a new product. Following a disastrous unaired pilot episode, the first full series of Game of Thrones finally aired in 2011, still several years before Netflix began releasing its own in-house commissioned programmes and transformed itself into a juggernaut.

The drama’s cultural status has benefited from being broadcast on traditional television channels, with the weekly release of new episodes creating days of debate over each new development. But with big-budget dramas increasingly made by global streaming services such as Netflix, who launch all episodes on their services at once and allow viewers to watch at their own pace, it is becoming harder to recreate that level of buzz.