Qualify your callers before you even call them back. Ask them simple questions like the price range of the house they're looking for. How much they want to put down, neighborhood etc. Your voice mailbox can be set up very easily to "interview" your callers for the needed information. An example might be, "So I have some potential listings ready to present to you when I call you back, I'll need a few details. First can I have your name please, dial any key when finished". The system records the callers response and says, "now can I have your address please, and dial any key when finished". . .All the responses are put together for you as one message.
You get all the information you need from the caller to completely qualify the caller
Eliminate the need to phone people back just for their details
Callers will be impressed with the sophistication of your company