Up, up and away in my beautiful 747

We are feeling like cattle again with the airport routine. At least they've been kind enough to give us fashionable ear decoration and not sort us by weight. We were informed upon boarding in Minneapolis that this flight is and I quote "extremely full". What exactly is the difference between full and extremely full when it comes to airplanes? Perhaps there is seating (most definitely not in first class) that passengers are encouraged to do a little cuddling and share seats with complete strangers.