In response to "Another Guy":
I don't blame Wal-Mart in the slightest for discouraging unions. From a business standpoint, they are about the worst possible thing that could happen in your business.
A union is basically a group of employees, or a joint agreement on the part of all or most employees that attempts to make business descisions without any formal experience. Because of their power, a union that holds a critical level of employees will kill a company from the inside out. To support a union, other parts of a business must suffer that will open the business to competition from outsiders or degrade the quality or service that the company can provide. The reason Wal-Mart destroys unions before they start is because they KNOW they can't afford them. They know their business will immediately become unprofitable due to the demands of an uneducated group of employees who demand more than the company can provide.
One of the biggest things I've learned in running my business is NOT to compete on price. Trying to make the lowest prices service or items severely degrades quality, or other parts of a business, and unless it can be done on a massive scale (like Wal-Mart has done), it is impossible to run a successful business based on providing lower prices. Wal-Mart works the way it does for a reason, and that's because it cannot afford to run it any other way.