The information you provide in your business answering machine greeting can vary depending on your specific needs, though some basic information is common. You should indicate the business that has been reached, including a specific name if you have a personal business number or extension. If the message is for general use, you might indicate that you are unavailable, though a message for use after business hours can provide the caller with regular business hours. You should not, however, use any language that could be taken to indicate that you are busy with a task that is more important than your caller.
While they are listening to your voice, they are internally deciding whether or not it is worth their time to continue or hang up. Look at your voicemail message as its own short advertisement.

You’ve reached the (name) family. We can’t answer your call right now. So why don’t you leave your name, age, sex, height, weight, phone number, a short message, your social security number, credit card number, how many kids you have, your mother’s maiden name, along with the date and time you called us. And if you’ve survived this message and are still listening, your message better be important.
Here's the problem with recording elaborate joke messages on your answering machine: Your answering machine will become more popular than the person who owns it. Friends would tell total strangers to call my number and listen to the new goofy message. They would become disappointed if I actually answered the call first. I would have to hang up and let the machine pick up just for other people's entertainment. Dozens of people were finally calling my home phone, but few of them wanted to talk to me personally.