Mark's company currently enjoys an exemption from the FAA to fly drones for commercial use. Mark says the lighter your drone is, the more challenging it is to fly. It's always important to have extra batteries. Additionally, it's important to always fly with someone else because your perspective is often skewed, and a second person can help you keep track of it.
There are some basic rules to follow, including staying away from airports, and don't use it to spy on other people. If you're going to buy a new DJI quadcopter, plan on spending twice as much for extra batteries and other accessories. Also, keep your flying activity on the down-low, so as not to attract unwanted attention.