It normally takes a good long while until consoles see price drops or discounts and sales at retailers. But the 3DS, only a few months after its debut, is being offered with promotional credit hoping to get consumers to bite.
Amazon.com is offering a $25 promo credit with every 3DS sold. You have to buy the 3DS outright, but you will get $25 to spend on something else, like a 3DS game.
Now that Ocarina of Time 3D is out, more people may be thinking of buying a 3DS, which could be a good reason for this deal. Or it could be due to the fact that the 3DS is struggling at retail, far more than anyone could have expected. That also might be the reason for a number of game cancelations.