Go to their site. Better yet use them like I did. I think you'll find you are wrong. While the carriers that use their load board are under a terms of use contract they are by NO means an employee of U-ship. They are independent contractors. U-ship is indeed a broker.
They charge brokerage fees. You can call it whatever you want but if they broker a deal between a hauler and a shipper and charge a fee for the service it makes them a broker.