A present of a father to his son

Sam is a very capricious 9 year old kid who has everything and never gets satisfied. Last year, his parents bought him an Iphone, an Ipod, an Ipad, an xbox 360, a doberman, a swimming pool, the headphones beat by Dr Dre, the whole collection of Angry birds, a travel to Los Angeles, and many other countless things.  This year, a few week before Christmas, Sam asks his Dad :"Daddy. Can I have a mac for Christmas?".

 "What??" replied the dad (expecting a new laptop) to make sure if it is what he really heard. Sam:"I saw that mac on TV, and I really want one, I won't ask anything besides." The father replied " You don't want a blackberry besides?". Sam:" That sucks! I want a mac!" The father ,very surprised, replied "Sure!" to his son very surprised too, by his answer.

Two weeks later, at Christmas, the dad drives his son to McDonald's and buys him a Big Mac.