One of the little-known facts about working in bike shops is that you end up with a lot of spare time during the winter months. There are days when all of the bikes in inventory have been been built up, repairs are up to date, and customers are rare as hen's teeth.
On those days, after you've dusted all of the tube boxes you can stand to dust, and aired all of the tires up that you can possibly pump, you start looking for stuff to break the monotony...the boredom of holding down a fort no one is assailing.
One of my favorite "dead-day" activities was the Figure-8 BMX Freestyle Bike Race of Death.
Basically, we would all grab a freestyle bike from the display (or ride our own, if it happened to be at the shop), and we would race around the shop sales floor, in a figure-8, around the front counter, through the display racks, and back around. With five or six riders, depending on the day, the action could get pretty exciting.
Typically, we would race until someone crashed into a display and broke something, or two riders would collide at the crossing point of the figure-8. At that point, we'd put the bikes up and start repairing the damage/attending to the wounded.
At least, then, we had something constructive to do.