People that are pirating the show aren't willing to pay. If they were then they'd be subscribed to HBO.
Same thing that happened with the music industry: people don't want all the filler bullshit on some albums, they just want the hot single. Let folks buy a single MP3 and they will, or they'll pirate if you only provide the entire album for sale.
You have the option of buying the DVDs or through iTunes. Using your analogy, they can buy the entire album or a single track. If a band played some new songs at a concert, you'd have to wait until they made it on an album...unless someone records them and releases them for free.
Andy Ihnatko nails it: http://ihnatko.com/2012/02/20/heavy-hangs-the-bandwidth-that...
But — umm — the release date is only, like, two or three weeks away.
Two or three weeks away would fine. Two or three months would be okay too. GoT season 1 finished airing in June 2011, and didn't come until out on DVD until March 2012.
My GF is completely addicted to Game of Thrones, but she openly admits she will not pay $540/year for basically a single season of a show.
All the "but look at all the other content you get" arguments are null, if I were interested in any of that other content, I'd already be paying for it. But we're not.
She can torrent it now and watch it when she likes for free. While she will undoubtedly go buy the DVDs when they're released (she always does), the incentive to watch it "now" as it's being broadcast is worth some amount of money $0<n<$540 for her.
I really don't buy the argument that HBOGo wouldn't make any money if they charged $15/mo for streaming-only access. Nearly everyone I know (none of whom have cable/satellite and HBO now) would gladly pay that price or even marginally higher.