Advantages: This works well when you can only have a few people over because only the people who read he away message will know. You won't have to feel guilty or make people mad when you forget to invite them.
Disadvantages: You might have unwelcome guests.
This method works best for last minute parties planned a few hours beforehand.
Spencer: what party? I wasn't invited! ::angrey glare::
Alex: oh dude don't worry, it was an Away Message invite, she didn't officially invite anyone. Just check the away messages more often.