Actually, restaurants do this now. It's more a matter of a supermarket needing choices and a restaurant knowing you're going to buy something regardless, so they can choose one brand over another.

This preferential treatment is fine, since a restaurants are service industry. Even though you receive a product, a restaurant is providing the service of preparation, location, quality control, and labor. Both video games and my example are products, falling into the market as consumables as opposed to services. By creating a situation where a developer allows or is forced by one market (PS or Xbox) into have a 'better product' available for an equivalent product, the markets are, in a way, product tampering. That's why I didn't say ShopRight was boycotting Coke. Different situation, and has a whole different set of connotations. They are specifically being paid to prevent a part of a product line from being offered, and by a competitor of that product.. Maybe a better example is this: Walmart gets to carry Diet Coke, but no one else does, because they paid Coke. And this is a huge issue many people have with this company in real life, aside from the essential rights and benefits they deny their workers. I know many organizations won't deal with them because they often insist on exclusivity.