Regarding Richard B.'s comments: My point is that it would not be difficult to conduct this sort of study in a fair and scientific manner. Whether they actually did or not, I don't know. If they were trying to be fair, the experimental design would obviously address the kinds of questions you raise. Random sample of dogs that haven't been trained to eat your brand, putting the same amount in each bowl and spacing them evenly apart. If they weren't trying to be fair, well, it is marketing afterall. They aren't making any claims about health benefits, or anything beyond doggie preferences. I don't think most people will blindly follow the outcome of this study, but they will give their dog what they think is best for them.