For instance, when I was already seated at the theaters and the previews were about to start, I searched for phones that have their BT on.

If there were any, I sent a message that they were entitled to either a free drink or popcorn and they should go to the snack bar and show them the message. This is sometimes a great way to get seats in a packed theater.

Same thing with restaurants. People think they're getting free desserts and such because they they got a message via their phone (they think it's some high tech lottery or something) and asking their waiters for their freebies.