Two Advantages to who? Consumers who want to keep practicing rights they don't have? Publishers? Developers? Microsoft?
I'll give you 2 for each:
Publisher+Developers:
1) People are buying your games new, no two ways about it. New or nothing. You are getting money for EVERY single game bought.
2) Microsoft's system for trading in and selling used games also gives you more money. You take a share of it! Nice!
Microsoft:
1) They take a cut of used games and trade in now! Making some money they deserve, nice!
2) They're in full control and will no longer have content stolen from them under there noses like they did with the 360, where people would buy a game, give their profile to their friends, and license transfer and now 2 people got the game for the price of one. If it happens now, they're in full control and will ban said accounts! Nice!
Consumer:
1) Every game you own is now in the cloud! Nice! Your copy of Forza Motorsports 5 no longer requires the disc, less luggage to carry around when you want to go to your friends house and play splitscreen with him! Less effort for you to play what you want to play since you won't have to swap discs.
2) Your Xbox will always be connected and will always be on! You can now always be in the known with your friends, you can now skype while you play! Built in game recording and live streaming! Watch TV while you play, and instant background updates!
This post has to be a joke.