Because...

Because of this not only do I want to see Charlie and the Chocolate Factory, but I also really want popcorn. And pepsi. Maybe some raisinettes as well? Oye.
The economics of movie popcorn pricing (kottke.org): "The economics of movie popcorn pricing posted July 25, 2005 at 11:40 am In the past 5 years, I've probably been to a theater an average of once every two weeks to see a movie. Even though it costs a small fortune, I almost always get a soda and popcorn (topped with 'butter'[1]) to go with the show. Many of the larger chains offer a deal if you purchase a large popcorn and a large drink together. This 'Super Combo' costs a lot less than ordering a L popcorn and a L soda separately from the menu but often it will actually cost you less than a L popcorn/M soda, M popcorn/L soda, or even a M popcorn/M soda (?!??). Why such a steep discount when the theaters make so much of their money on concessions? I've developed a few theories over the years but would like to hear your thoughts before sharing them. [1] The proper way to butter movie popcorn is to fill the bag half full, apply butter, fill the rest of the bag and apply more butter. This results in fairly even application of butter to kernel throughout the bag. Due to a lack of focus on service and an increasing number of theaters moving to DIY butter application, it's getting more and more difficult to buy a good bag of buttered popcorn at the movies."