There is an interesting article on [URL=http://www.wired.com/news/games/0,2101,55955,00.html]Wired[/URL] that comments on the rough situation some game developers have to go through because of content restriction applied by certain big retailers, in this specific example, Wal-Mart.

Dominating about 25% of the videogame annual sales in the US, most of the mid sized publishers sure need the kind of exposure a big retailer could give them, even when it comes at a price. Some examples that apply to this would be BMX XXX, Giants and even Duke3D...

However, Wal-Mart's policies go far beyond saying no to a 16-year old at the cash register, say game developers and industry analysts. The company's purchasing managers also review games before they're published to ensure every aspect of the product -- from packaging to content -- toes the line with the retailer's conservative policies.