That’s the trick. You have to find out what the majority of people want, and how they want to go about doing it, and generally fill that need as simply, and obviously as possible. Sometimes though you need to ‘retrain’ people, and when you do THAT you have to be even more careful, to make it as obvious as possible.

Taking your theater analogy a little more closely though, it’d be like saying “Well 90% of theater goers buy a medium popcorn and large drink, so lets just give that to everyone right of the bat when they walk in the door nad include it in the ticket price.”

You have to consider, will you lose the 10% that you are forcing to get the popcorn and drink? Would you lose the 90% if you don’t do it? Are the other theaters doing it? Does it save you money to do it? Does it get the moviegoers into the seats quicker? Maybe it makes sense to give them the popcorn and the drink automatically, and maybe it doesn’t. On the other hand the theater has to make decisions about what they serve. Do they need to give their users tacos, and pizza, and hot dogs, and hot peanuts, etc, or can they get away with just popcorn, and candy.

Just because that salesguy says that people like sushi, doesn’t mean you should put a sushi bar in the theater.

Anyway yeah. You have to give people what they want, and what they need, but not any more than they really need, and not just something because they want it.