Generally, people that call and leave messages are more likely to be ideal customers of your business. Your voicemail message is often not much more than a formality to the person calling.
The most engaging messages are slightly unique in nature. They combine a mix of clever scripting and music. Slight humour is often used to promote a product or service and is usually quite effective. It's also very important to choose both the written and spoken tone that appeals to the characteristics of your audience. If your target market is the younger generation, a script that includes slang words and is quite laid back would be an excellent choice. If your target market is primarily business professionals, then a more articulate choice of words would be more suitable.

And this one (from Brad Lund, of Baltimore) made me giggle loudest and longest: "This is the Lund residence. The answering machine is on vacation. This is the refrigerator speaking. State your message slowly and clearly. I'll write it down and stick it to myself with one of those little magnets."
Recognize Their Need. When someone calls your business, the voicemail should give them a sense of validation. This means that your voicemail should extend gratitude for their interest in your business, or an apology for not being there to answer your call. These two simple courtesies can go a long way in the creation or establishment of client/business trust. Make it Informative for the Caller. Your voicemail must include all the information the customer will need for your particular business. For instance, if you’re a brick and mortar establishment, it’s wise to include your store hours. It’s also a good idea to leave them an alternate way to contact you, especially if it’s after hours. After all, you don’t want to miss just one potential customer. Here are some suggestions for elements to include in your voicemail: Business name Hours (if brick and mortar) Alternate method of contact, such as email Your name