Leslie,
It would seem as though no matter how few calls you get, you would still have to pay the service, correct?
I have no idea who well the following works, because I haven't used it. My friend does, and he swears by it. I know everyone has heard about it by now. He uses OneBox receptionist. I beleive he pays $30.00 per month. He completely dumped his answering service. The way it is set up, OneBox will set up your greeting with a professional voice. It explains to the patient that they should call back in the AM for all non-emergent things. If the patient MUST speak with the on call doctor, they should push 1, and the call goes to his cell phone. For any messages which are not emergent, press 2, and they go to voice mail. The nice thing about the voice mail is he is alerted by a text message that a voice mail has been received, which can then be retrieved by telephone, email or going to the website.
I am not sure I have it exactly correct. If you want anymore information, I could probably have him type it here. Just another method.