Lead has zero calories, does that mean we should be eating it by the pound? How about mercury?
But seriously, this is just another example of the manufacturer playing with the serving size. Like fake potato chips, they know you "can't just eat one" and will wind up finishing off the whole box, so it's pure profit for them to sell you something that cost them a few cents, but was sold to you for a few dollars a box.
Remember kids, there's a huge industry out there, a trillion dollar one, whose only reason for existence is to spin reality to whatever their clients want it to be. There are many good resources out there that tell you how this works. One is called "Positioning, the Battle for Your Mind" I was lucky enough to have had a professor in college point us to this book - it was a class I initially expected to be useless fluff, but it really opened my eyes.