I use call measurement and have a number for each source. I have a different number for new and used vehicles on Cars and AutoTrader.
I am usually the one listening to the calls but lately, I have a manager in each of the stores that has taken an interest in listening.
I always have a call to action in my descriptions. "At this price, this one won't last long", "Priced, below market, this one will go fast", "We use market-based pricing to ensure that our vehicles sell fast over the internet" "Call now". I have dozens. I want the customer to call rather than send an email. If you aren't listening to the phone calls, I promise, you have idiots taking the calls.
With Call Measurement, you can send the really bad calls to their manager's phone. It usually gets an immediate reaction. I have a hard-fast rule, idiots don't answer my phones. I told the receptionist that certain people are allowed phone calls. The others, don't let them answer even if their wife is calling.
Chris, Phone ups are at the very bottom of the funnel. Not handling these properly is very expensive. You are stepping over dollars to save dimes.