Kern Scheduling Services (KSS) is a mystery shopping company that acts as a clearinghouse for other mystery shopping companies and helps schedule their shops. For example, mystery shopping company A may be a small company that then outsources their scheduling to Kern Scheduling. You'll find many shops listed on this site from many different companies and may be a good beginning point for a new mystery shopper.
If you're new to mystery shopping, please read my Mystery Shopping 101 post here for guidelines and tips and check out the other mystery shopping companies I have discussed by clicking here.