those 100$ gift cards were wal marts idea,sony doesnt give em away

A more important question is how much money is Sony still losing on each PS3 sold?

The massive surge in sales could actually COST them money (edit: in the short term). Of course, royalties from MGS4 could partially offset that. Though many people have speculated that no or low royalties could have been part of Sony's exclusivity payment.

I'm not sure if Sony has profited for it... but a whole lot of lucky new PS3 owners sure have.

Wal-Mart probably just discounted it because they overbought on Blu-ray and had a huge backstock of PS3s and other blu-ray players.

Most retailers did thought Blu-ray was going to start smashing the non-competition in the next gen format wars and pick up substantially.

However that hasn't been the case. Growth rates have been lower then expected.

This moves both overstocked PS3's and Blu-rays out the door by just discounting PS3s.

The fact that only walmart is doing the $100 gift card proves that wal-mart is taking the hit.  Remember its on all blu-ray players not just the PS3.   If I remember correctly blu-ray players have at least a $100 profit and more depending on the model.    I believe the Sony blu-ray player that retails for $399 costs about $265 for retailers.   Retailers make barely anything on the PS3.  I believe the store I work for makes about $15 off each PS3 sold.  Not sure about the $499 bundle though.   They do the gift card deal cause Wal-mart isn't losing $100 off each sale because people are going to use those giftcards which in return will do two things a) they will use the gift card and spend over $100 so the hit will be very small b) Buy products with the gift card that have high margins such as clothing.  

I can bet you that sony loses less money selling the $499 bundle compared to the $399.     They aren't paying konami $60 a pop for each bundle.  Probably half that or even lower. 

That's not exactly true. It's highly likely Wal-Mart is the one taking the hit.

But it's possible that Sony paid them to. You pick a few retailers (or one if it's big enough.) and get them to sell theirs at a loss at their store and pay them a kickback, and you get increased sales... yet you can control just how much "loss" your dealing with because you can only lose as much as that chain of stores have stock.

They also sometimes do it to target where other companies are stronger to try and steal from the competition. (Like Wal-mart where Wii is stronger their then other places and HD consoles are weaker then normal.)

There is a company that sells plug in drives at a loss just to screw the company strongest at best buy. (Though they hide their name having Best buy brand them as "Geek Squad" drives instead of the real company.)

Additionally, this deal could of originally excluded the PS3.  Until Sony decided to throw some money in to include it.  Since retailers make money off Blu-Ray players... but not PS3s.

These are all unlikely, but possible. 

 I've heard this is the case.  Though i can not personally confirm it. 

Don't forget that they ar enot giving you $100 cash. Walmart is giving you gift cards that you can only use at their stores. Here is my theory:

$50 = loss profit
$20 = profit from your $100 gift card purhcase. They get their money back.
$30 = only actual loss but...........

Sony kicking in some incentives to Walmart for the bundle and promo

$15 = only actual loss by Walmart. Not much... Two hours pay for an entry level worker

that depends on what you are buying. Wal-mart makes barely any profit on most of their items, that is how wal-mart runs their business and why most companies can't compete. If you buy blu-ray discs/video games/CDs then the loss is minimal, but if you buy household products then wal-mart would lose a lot of that.

Walmart did it so they would have a larger market to sell $30 movies to

didn't gamestop/ebgames also match the 100 gift card?