You Don't Wanna Leave A Message

Jack hands out his business card and tells clients that if they call and his voicemail picks up, that simply means that he's either on the other line and can't answer or he's with another client or he's momentarily away from his desk. If you leave a message, though, and clearly state your name and phone number, Jack will call you back as soon as he can. Jack explains voicemail as if the concept is brand new. He imagines people calling him, hearing his voicemail recording, and instantly freaking out. Jack doesn't want you to freak out. Should he explain again how the voicemail works?