Here's how you get people to wait nine hours in the middle of a conference to see your marketing stunt: Build a ghost town, write hundreds of pages of script and pay a lot of money to bring every little detail to life.

HBO's "Westworld" activation at SXSW was beyond anything many conference goers had ever seen at the show. Tickets were gone each day in the snap of a finger, and those who opted to chance the standby line often had painfully long waits. Elon Musk himself paid a visit.

Those who could get in began their experience at Austin's EastSide Tavern, where they were assigned a black or white hat (after a "personality assessment"), then hit the road in a shuttle bus. Twenty miles outside town, Giant Spoon had found a ghost town to make the show's Sweetwater into a real place — complete with actors, immersive storylines involving the visitors and enough stiff drinks to forget that brisk wind kicking up dust everywhere.

"The idea of 'Westworld' the show—it is an immersive entertainment experience. Guests travel to a park to live out their wildest fantasies. It really was a no-brainer for us to bring that to the real world," says Steven Cardwell, director of program marketing at HBO.

That said, "Southby is a really tough place to come as a brand, because everyone does it and you're always trying to figure out how can you break free and break out," Cardwell says.

Check out our behind-the-scenes look at how Giant Spoon and HBO created the experience in the video above.

And see our other SXSW Remotely Entertaining videos right here.