I'm not exactly sure why they're making it so hard, but Game of Thrones will have special theater screenings of an episode from Season 7 for those who buy the Season 7 DVD (there is no mention if the Blu-ray is okay). So, with proof-of-purchase you can
register for the free screenings at the times and dates below. You do get two tickets per DVD, but you ain't getting in without proof of buying the DVD. Oddly, if you own the DVD, why would you want to see an episode that you got for home viewing? The only comparison I can think of is when you buy a movie as its sequel comes to theaters you'd be treated to money off the new film or possibly a free ticket to the new film.
This is such a weird, but free event.
