How do video games get sold out?

I wanted to buy New Super Mario Bro. Wii for my wife.   I wanted to wait until after Christmas to see if I could get it cheaper.   So a few days before Christmas I went into my local Wal-Mart to see if they had any of the game in stock, come to find out they were sold out. Although it is not the best game on the Wii, it is very popular because of Mario. Anyways that being said, Nintendo had to have known that it would be a big seller this holiday season, so why are places sold out? How hard is it to manufacture these games? Especially ones that everyone knows will be popular    

Everywhere I go I try to hold the door for people.

I do it every time my wife gets in the car.

But the one place I do not hold the door is the Post office.

For some reason when I am heading to the post office I could care less about courtesy.

The moment I get out of the car, I grab my package and run to the door.   Taking down anyone in my way, just so I can be one person ahead in line.

My Woman is freaking out about her job and what she wants to do for her career. 
We are suppose to move this weekend and she is so crabby and depressed, I have been doing all the work!! 
Which means I don't have time to play any videogames and then that makes me crabby. 
I did get my Nike Air Max 2009+ $160 running shoes for $90 and they look/feel great!!

Halo Waypoint is supposed to drop tomorrow.  
I am not sure what time, but I will be up at 6:30 with my Xbox on. If not then, I will be going home for lunch to check.  
Ok I am not that good at the game but I don't have the kind of time these 13 year olds do. 
Not to brag but back in the day I was ranked in the top 15% on the original Socom.  A different time and a different life. 

What Playstation game should I get during this Sale

The Force Unleashed just dropped to 18.99 at Gamestop!!
I am seriously considering buying it.
I got a $25 for my birthday, but I don't want to waste it on a game that might suck.
Their have been mixed reviews so I guess I will take a chance

I finally Quit my part-time job at The Sports Authority.

That job was sooo boring.

I quit because I did not have enough time to play video games.