Maybe they are misusing a SATA connector for their own thing?
Comparing SATA to USB 2 makes little sense to me with their numbers. A SATA-III interface is theoretically about 12 times as fast as USB 2. It's 6.000 Mbit/s for SATA-III, 480 Mbit/s for USB 2, not considering protocol overhead, which is large for USB.