It was a bubble.... and as we know, bubbles are neither created nor popped by any one entity. This time it was the airlines, banks and bloggers all contributing to the orgy until the airlines realized that they were getting the short end of the stick. And they ultimately controlled the product.

The interesting question to me is where things go from here. The UA devaluation hasn't entirely killed the model -- such as a revenue based award chart would -- it's just made it a lot more work.