The automated personalized greetings allow you to quickly create a voicemail greeting of your choosing that gets personalized to each of your callers. You no longer have to take the time to record individualized greetings, and, you no longer have to use your own voice in the greeting (it’s true, some users simply don’t like to use their own voice!). Never end up like Jason in this vidéo :
Keep it Brief. Time is money in business, so if your voicemail is long, chances are the caller will simply disengage before the cue to leave a message even sounds. Keep your voicemail short. The most should be around 30 seconds, and even that’s pressing it. We’ve grown into a country where our attention span can last only about 10 seconds in some cases, so keep it short, brief and to the point. Persuade and Engage the Caller. If someone calls your business, they already have an intention. It’s the quality of your voicemail that plays a factor if they consider you a company they’d like to deal with. This is your chance to motivate someone to engage in a meaningful conversation with you. If your voicemail is shoddy, chances are they’ll hang up, or lose motivation to continue the call. In other words, your voice mail must engage and entice someone to the point that they care enough to leave you a message.

In Provide the caller with these options, select an option. Some options will prompt you for additional information, such as an alternate phone number or text to be read to the caller.
At present, you have to record your greeting by recording directly into the iPhone microphone -- the results of which are average, of course.