When the apple employee left the iPhone at the bar it wasn’t because he forgot it. He left it there in the purpose of commercial. Isn’t that a great way to make people curious? The majority of people will start talking about it since he “dropped” it. It will also reach out to a lot of people since it will be mentioned in tv and newspapers. But as I mentioned it will be a great way to make people curious. Not all people will think of it as free commercial. The unthinking majority will think as you “What a clumsy guy, how can he drop a prototype on a bar?”