Why don't movie theaters do merchandising?
When people are done seeing a movie, there should be a shop that sells copies of the soundtrack, copies of the other movies in the franchise, related toys (as appropriate), etc. They could even sell the Blu-Ray of the movie you just saw (whether restricted sales to movie-goers, sold to anyone, or pre-sold with day-of-release delivery).
There is so much in the way of movie merchandising, and the theaters seem to completely miss it. Even if they're contractually locked out (which is stupid), they could lease a separate store adjacent to the theater that sells movie merchandise. (Perhaps I should start that chain--too bad I already have a good job.)