Should you leave a message?

The Marketing Mix:

"Very often, when you are reaching out to prospects who've never heard of you before and you make an initial round of phone calls, it's essential that you leave a message. Frankly, if you don't, it's a waste of time. You may think it's not worth leaving a message, but that only makes sense if you think that leaving a message is about getting a call back. Don't expect that. People rarely call back these days, which is fine.

What's realistic is to leave a message as your first volley, your initial introduction to a stranger. Don't even think about them calling back. Next, you follow up with an email message that says the exact same thing as your voice mail. They may respond to that, but probably not."