Lead qualification is the step of separating serious buyers from casual visitors, usually by a few questions asked at sign-in: whether they already have an agent, their timeline, and their financing. It turns a flat list of names into a ranked callback order.
A little qualification at the door saves hours on Monday. An unrepresented visitor who is pre-approved and buying in the next few months is a different lead from a neighbor who came for the snacks, and you want to know which is which before you start calling.