Walmart is the world's largest retailer, but has extremely low margins. They amass massive profits based upon their massive volume, but they kill the profit margins on the vast majority of all products. Walmart will actually meet with a manufacturer and tell them point blank how much they will be selling the product to them for and all the other items that they (the manufacturer) will pay for. Many buckle because they see a potential massive audience for their product, but others won't buckle because they know the the big box stores are notorious for destroying margins particularly of specialty products.
Great example: A company that my company used to carry their product (and we were the largest retailer of their product outside of Target back a decade ago) decided to get in the mass market business. They gave Target a rate of $1 less per unit than we were paying and we were paying .75 less per unit than all other retailers, however, Target took a product that retailed at $12.99-$14.99 and brought them in at $9.99, which was all part of their numbers game. There was no reason to price the product below what had been the average market price as the product(s) literally were flying off the shelves. So, our retail went from basically $15 to $13 to $10 within six months per unit and our margins were killed thanks to the big box. And the big box made the products overexposed and no longer able to sustain the margins that made them fantastic for retailers all over the world. Target ended up clearing out all of these products at below wholesale cost by the time they were done with it.
Another interesting thing on the manufacturing end when dealing with a large (or massive) big box chain: You as the manufacturer not only agree to the pricing that they want to pay, but you as the manufacturer have to pay the costs of essentially stocking the product in their warehouses. If they don't move product, not only do they get to write it off, but the vast majority of contracts stipulate that they can return all unsold product if they so choose to. Target used to (not sure of present day) have the ability to claim a return as long as they were returning at least part of the packaging. So, this guy's company would get all of these returns and many of them without the product and he still had to reimburse Target for the wholesale cost, let alone the fact that he had to pay to have it shipped back to him. It's nauseating. Not long after his foray into big box retail, he sold the company. All that I can say is that they are major toy company in the United States and have exploded in growth over the past decade, but they've had to radically increase their product offerings and have decided to "deal with the devil" in big box.