Selling 600k copies of an album priced 15.99$ in 3 days is the equivalent of selling about 9.5 million singles priced 0.99$ in 3 days. Call me when a single does that.
King B ha power.
Gaga and her team must take notes.
Without hype and promo = 500K in 2 days
One more year endless hype + 3 months pre-order + many naked photos and videos + discount + desperate twitter message + live performances = 250K in a week.
King B 
The release strategy was a brilliant idea, I'm sure many will try it and fail.