This means absolutely nothing. These units could be rental properties, where the landloard is a realtor or hired a realtor to manage the property, and they leave them there for convenience when they need to access the property. In addition, some of these, especially the smaller ones that have a dial combination are probably additional lockboxes that have gate transmitter or key fobs to actually enter the building. The SANDICOR box usually only has the keys for the house, and additional transmitters, etc are often stored in other lock boxes.
In my building, 50% of the lockboxes are actually rental properties, not for sale.
