Originally Posted by Noddy

Getting off-topic again but Walmart does the same thing to their supplier. Business owner thrilled to get his new widget accepted into Walmart, expands his business to meet the demand. The following year Walmart comes back and orders more and more but tells the business owner they will pay 15% less than previously. The business owner now has a bigger factory and more mouths to feed so he cuts his profit margin. This process keeps repeating until the guy (who by now is sorry he ever met Walmart) either moves the business off-shore or goes bankrupt.
Read "The Wal-mart Effect" by Charles Fishman if you are interested in the topic.