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.
If you’re actively looking for a telecommuting gig, or you’re a small business owner looking to project a polished, professional image, do yourself a favor and call the number you’re giving out and listen to your voicemail greeting or, heaven forbid, see how your phone is answered by whatever family member happens to pick up the ringing phone. Are you impressed, or embarrassed? Was it useful, or was it a colossal waste of your time? Could you understand every word clearly, or did it sound like you were in a tent in the middle of a monsoon? Is the information you provided recent, or was it dreadfully out of date? Did it sound like someone you want to work with or hire? Or not?

These issues limit the quality of the recording because the amateur actor doesn’t know how to speak with the proper enunciation and cadence for phone system recordings, and there’s no experienced director handy to provide guidance.
In an ideal world, voicemail would be unnecessary. There would always be someone available to take customer calls and no one would complain about their calls not being returned and/or rejected. But of course, this perfect world isn’t possible. That’s why it’s important to give your callers options when you are unavailable. For example, aside from leaving a message, callers can also choose to listen to some relevant information about your business (such as a list of your services, your address, directions, hours of operation, and more).