Voicemail greetings are simple things, and in a business, they can seem unimportant. However, a voice mail greeting gets a lot of play with customers and associates—think of how often you are unable to take a phone call because you're on another line, away from your desk or out of the office.
"[Auto-attendants] assist a business of any size in presenting a more organized, efficient, and, if necessary, more robust picture of itself,” points out Brandi Armstrong, Co-Founder of Telecentrex and blogger on evancarmichael.com. The right greeting can make the difference between a frustrated customer or a satisfied one.

-Hello. I’m sorry I didn’t answer your call. I’m just waiting for more important people to call. If I hear your message and deem you worthy of the title “important,” I will think about calling you back, but for now. Bye! -Beep-
In certain situations, it’s a good idea to let a call go to voicemail. If you’re in a loud area, unable to spend 10-15 minutes talking, or are otherwise distracted, don’t answer. Recruiters who cold-call candidates will understand that you’re simply unavailable – but make sure to return calls in a timely manner. If possible, call back during regular business hours.