Fascinating. This book excerpt tells the story of a WalMart in Quebec that unionized, only to be shut down. Walmart claims the store was already underperforming, and adding 30 more people to fill union worker demands wouldn't make sense, so a shut down was the only option. Workers claim Walmart was just playing hardball to send a message. Some people think the union leaders new this would happen and used the union workers to generate negative press towards WalMart.
Regardless of the real reasons, this is why WalMart will ultimately slow down. Size brings tons of problems, like the fact that everyone wants to take a shot at you.