In an elevator there is nothing to do and most times mobile phone don’t work in an elevator. So why not entertain people with a message/advertising? Make it simple, have a message handwrite on a piece of paper.
But why stop there, find a way to make your message turn upside down when the elevator goes down and up again when it goes up. Massages as prices goes down will be trusted when the elevator are on its way down. Brands that talk about higher values will be believed in the elevator when it’s moving upwards.
This will make people to talk about it. If you can get your massage as effective as an elevator pitch, then the elevator will turn into a “buzz machine” (where word of mouth spread upside down).
An elevator pitch is a brief overview of an idea for a product, service, or project. The pitch is so called because it can be delivered in the time span of an elevator ride. Wikipedia.org
Here is a short video on how to deliver an elevator pitch. Watch it then go to your nearest elevator and start practice (don’t start with your CEO).