Read an article where McD was pondering on what to do with the Double Cheeseburger price as the profit margin on the burger was diminishing and yet it was a very popular item on their value menu. They went through different options one of which was to remove it from the value menu but they were in agreement that a similar item at that price was needed to bring in the store traffic. Thus the McDouble was born. Of course it doesn't help that some people only order the McDouble and nothing else, e.g. high margin sodas, like yours truly .