game_of_thrones_titleWhen Sky Atlantic launched in 2011, few outside the company could have predicted how important the channel would become to Sky’s efforts to stop customers moving to rival pay-TV providers.

Back then that largely meant Virgin Media which just a couple of years before had signed a long-term deal to secure access to ‘all’ of Sky’s entertainment channels following a 20 month dispute which saw its customers lose access to Sky One, Sky Arts and Sky Sports News.

When Sky Atlantic first launched, many Virgin customers expected the new channel – and its exclusive line-up of HBO original programming – to be added to their EPG.

But Sky wisely kept the channel to itself.

Until recently, if you wanted to watch shows like True Detective and Game of Thrones you had no alternative but to pay Sky, either through its main satellite business or its NOW TV streaming service.

A look through various TV related forums shows how canny that decision was – GoT fans are often to found lamenting their ‘inability’ to accept a cheaper offer from Virgin, TalkTalk or BT because they don’t carry the show.

Making Sky Atlantic exclusive to its own platforms has dented the appeal of rivals and reinforced perceptions of Sky as a premium service.

While Apple’s iTunes and rival Blinkbox eventually managed to dent Sky’s exclusive hold over HBO’s shows by securing the rights to sell past seasons as digital downloads, neither are as closely associated with them as the satellite broadcaster.

That’s to be expected. Few UK households own an Apple TV and a surprisingly large number of people find connecting their tablet or laptop up to their TV either too much hassle or too complicated.

As a result, most homes rely on a single set top box for all their viewing and recording pleasure and so those wanting near-exclusive content naturally flock to Sky where it’s most easily accessed.

But Sky’s near-stranglehold on Game of Thrones has just been broken by rival pay-TV operators TalkTalk and BT who’ve both announced deals with HBO to sell the show via their YouView set top boxes.

TalkTalk’s customers must wait until next month to start spending, but BT’s can already get their mitts on a selection of HBO shows to watch in HD on their set top boxes, or on their laptop or tablet while on the move.

This is a big gain for both firms who, like Virgin, can’t offer Sky Atlantic and so find it harder to win over potential Sky switchers – something BT finds harder than anyone because, unlike Virgin and TalkTalk, it’s been unable to reach a deal to carry Sky One, Sky Living or Sky Arts.

Its HBO deal means that, despite the stand-off with Sky, BT can offer existing and potential customers the first season of True Detective, all of Entourage and the first four seasons of Game of Thrones. The fifth season is expected to be available within days of finishing on Sky Atlantic.

For many die-hard fans even this would be too long to wait and they’ll continue paying Sky or NOW TV.

But some potential switchers will weigh up the savings to be had from waiting a few weeks to buy the entire season outright on a platform that costs as little as £5per month and decide that the slight delay makes sense.

By the way, it’s not just Sky that risks some of its marketshare being chipped away by TalkTalk and BT’s move into buy-to-keep content.

Last year, before either had launched a download to own option, I speculated about how both ISPs could use YouView to take on iTunes.

This month’s HBO deal is the biggest sign of this happening. TalkTalk’s pricing is yet to be announced, but at the time of writing BT is selling HD seasons of Game of Thrones for £20.99 – a full £3 less than Apple’s digital store.

There’s a new wave of competition coming in the UK, but unlike the States where all the talk is about cord-cutting, it’s pay-TV firms who are driving the agenda.