You may already have a system. It is probably a person, and they are probably busy.
Before adding anything, it is worth naming what is already in place, because most brokerages are not doing nothing. They are doing one of three things, and each of them works right up to a specific point.
The junior broker
Common, and the best version of the three. A newer broker takes the sign calls, qualifies them, and hands over anything real. They learn the market by doing it, which is genuinely how the business gets taught.
Where it leaks: they are also prospecting, touring, and building their own book, so the coverage is whatever is left. Sign calls come at 8am, at 6pm, and on Saturday, and a junior broker at their most useful is out of the office at all three. It also puts your best inbound in the hands of the least experienced person, which is fine on a vendor call and expensive on a national franchisee.
The assistant
Reliable during business hours and much better at the administrative half than any automated system. An assistant who has worked a center for two years knows more about it than a script ever will.
Where it leaks: they cover the hours you are also covered, so the marginal gain is smaller than it looks. The calls you are actually losing are the after five ones. And an assistant answering for six listings is doing the same context switching a call center does, without the scripting to fall back on.
The shared inbox
Fine for portal leads, which is what it was built for. LoopNet and Crexi inquiries are email and belong in an inbox where somebody is accountable for clearing it.
Where it leaks: a phone call never reaches it. The inbox handles the channel that already produces a written record and misses the channel that does not. That is backwards, since the sign call is the one with no paper trail and the highest intent.
What to add, if anything
If you have a junior broker who wants the calls, give them the calls. That is a better outcome than any product. The gap worth closing is narrower than most vendors want it to be: the hours nobody covers, the properties nobody has memorized, and the vendor volume that makes everyone stop answering an unknown number.
A line that belongs to one listing closes that gap and nothing else. It is not a replacement for a person. It is what picks up when the person is in a showing.
$99/mo per listing. Cancel when it leases.
Questions brokers ask
Do I need anything if a junior broker already takes the sign calls?
That is the best of the three common setups and it is genuinely how the business gets learned. Where it leaks is coverage — they are also prospecting and touring and building their own book, and sign calls come at 8am, at 6pm, and on a Saturday.
What about an assistant?
Reliable during business hours and much better at the administrative half than any automated system. An assistant who has worked a center for two years knows more about it than a script ever will. The gap is the same one: the hours when nobody is at a desk.
Where does a shared inbox fall down?
A shared inbox catches what somebody already wrote down. A drive-by caller does not write anything down.