Many things, I'd say. For one, you can count how many people attended the IT Show.
You can also count how many people are just looking around, or just checking the items.
Or stand -- in awe -- in the escalator and see how many people are flooding up and down the building.
Or just buy a laptop cooling pad for $5. And a Philips earphones for half the price. I got mine for $11. Hehehe :-P