This way I know where I will be staying, if the elevators are close by etc. I want to know if the cabin I choose is forward, amidships, aft, port or starboard side, and if lifeboats or any rigging is going to block my view. Is the balcony full size or lesser because of a ship configuration? As a bonus they will sometimes offer you cabin $$$ credits or a meal in one of the extra charge restaurants. Be a smart shopper and do a few extra steps to get exactly what you want and expect.