Well I have since found out that the FAA has shaky jurisdiction at the very best on this, but before anything has changed the 333 is mostly useful if you are working with customers that are skittish, or if you are to get insurance. Check Peter Sach's website, or facebook page for a little info on that. Also the UAV Legal News and Discussion group on facebook are full of attorneys, lawyers and other people who have been to law school. Most people have been getting them just so they can have some insurance or get hired instead of our of real legal obligation. This is to change soon though.By law you need to register an aircraft, have a license and have operational approval to fly a drone for commercial profit in furtherance of your business...
https://www.faa.gov/uas/legislative_programs/section_333/
Now I'm not sure what they would do if you flew without one and got caught as they're still sorting out the legislation...