The hit HBO fantasy drama Game of Thrones has confirmed its place as the world's biggest television program.
But in a broadcast world of changing metrics and multi-platform algorithms, the fullest picture of its success may still take days to emerge.
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The first episode of the show's penultimate season drew an overnight television audience of 10.1 million viewers in the US, with an additional six million watching via HBO's streaming platforms HBO Go and HBO Now.
The total US audience is 16.1 million, but will increase as US +3 day and +7 day DVR playback data, seven day US streaming data, and international audience data from partners such as Foxtel in Australia and Sky in the UK.
In Australia the broadcast set a pay television record, with almost 900,000 viewers tuned in.
And in the UK the episode drew roughly 2.8 million combined viewers for a 2am simulcast of the US broadcast and a replay at 9pm in the show's regular timeslot.
The UK broadcaster Sky says the show's total audience could reach around 4.5 million viewers once seven-day catch up viewing data was added.
Most broadcasters were reporting lifts in the show's audience of between 20 and 30 per cent year on year.
![Arya Stark in Game of Thrones.](http://web.archive.org./web/20170720013136im_/https://www.fairfaxstatic.com.au/content/dam/images/g/x/c/y/2/p/image.related.articleLeadwide.620x349.gxd6ze.png/1500401352830.jpg)
All of those totals will change as data from ancillary platforms is added.
At least a third of the total US audience - a proportion which will most likely increase in the coming days - watch the program via streaming or web-delivered services.
There were reported technical issues from several broadcasters which caused their systems to crash under the weight of demand, with reported outages in the US, Australia and Latin America.
"We are devastated that some customers experienced technical issues tonight,' Foxtel spokesman Bruce Meagher said.
"As was the case in the US and Latin America, the unprecedented rush for a subscription just prior to the telecast crashed the system," Mr Meagher said.
Both HBO and Foxtel are repeating the episode a number of times across their seven day schedule.
While the Australian broadcast seemed to be beset by the worst of the outage, it nevertheless managed to break audience records for pay television in Australia.
Foxtel confirmed today the broadcast set a record for the most watched series television hour in the history of subscription television in Australia.
The broadcast on Foxtel and streamcast on Foxtel Now drew a combined national audience of almost 900,000 viewers.
The series "broke records worldwide cementing its place in television history as one of the most watched programming events of all time," Foxtel's director of television Brian Walsh said.
"The audience is unprecedented for Foxtel and we are ecstatic with the result," Walsh added.
Mr Walsh said he expected the total Australian audience figure to lift to around 1.5 million viewers once replays across the week's schedule and on-demand streams were factored in.
Mr Walsh said he "reiterated" the company's disappointment over the streaming outage.
"Foxtel engineers are working to resolve the issue to ensure smooth transmission for the remainder of the series," he said.
Foxtel also reported a surge in subscriptions to its streaming Foxtel Now service.
Game of Thrones is included in the Foxtel Now "drama pack"; in cost terms it is the least expensive way to access the program across all of Foxtel's services.
Foxtel reports the Foxtel Now subscriber base increased by 40 per cent in the 48 hours prior to the broadcast of the season seven premiere.
While the actual numbers Game of Thrones is pulling in are only roughly equal to the most popular shows on television, the scale of the series is what sets it apart.
Consider that when Game of Thrones premiered in just 2011, it pulled 2.2 million viewers.
The exponential increase in audience in such a short space of time confirms what many have said about Game of Thrones: that it is that rare television creature which builds its audience every year.
Most television programs, in contrast, peak in their second or seasons and then gently decline in audience volume.
In the US market, the zombie drama The Walking Dead has dominated the ratings narrative for the last decade.
However as Game of Thrones approaches its concluding seasons, it has soared in popularity.
Global audience data is difficult to compile due to inconsistencies between measurement systems, however broadly speaking Game of Thrones is the most dominant television program in global terms.
The top five programs in 2016, as compiled by the data company Parrot Analytics, were Game of Thrones, The Walking Dead, Pretty Little Liars, Westworld and The Flash.
Parrot's data included ratings data, peer-to-peer sharing and social media noise.
The series, based on George R. R. Martin's book series A Song of Fire and Ice, has become HBO's most valuable programming asset.
The current season, its seventh, is its second to last.
The series will end with an eighth season which will air in either late 2018 or early 2019.
HBO is already canvassing its post-Game of Thrones options, including a number of potential spin-offs, and at least one prequel.
The show is now HBO's most watched program ever; until 2014, the record for the most watched show in HBO's history was the crime drama The Sopranos.