Probably you have to get permission/pay for the spot. But what a kick it would be to have a pseudo cart with various headlines and websites.
After a moment of shocked silence, I bet they pack up quickly, making sure their coffee doesn't spill of course, and then off they run. Maybe one brave soul might mutter something as they go by. The added benefit will be those at the market being informed of what is happening with JW world and avoid it.