It's hard enough to catch your prospects in the office and engage them in a conversation. It's twice as hard to get someone to return a voice mail. Therefore, you must weave in a reason/benefit that's
What can you say? What value proposition can you share that will make them want to return your call? (I can assure you, wanting to "schedule a meeting with them" or "send them some information" is not going to make your phone ring off the hook.) What problem can you solve for them? What have you done for other companies like theirs that they would be interested in hearing about?
3. Don't Give Away the Farm.
If you tell them in the voice mail everything you'd want to tell them when you finally have the chance to speak or meet with them, then what's their incentive to call you back?
4. Create Five Unique Voice Mail Messages.