Should know it as well as I do, there's something about muscle milk.

The concept is simple.  Mothers milk is nourishing it helps an infant grow and develop muscles very very rapidly.  It provides all the sustenance that an infant needs from the age of zero up until three to six months and theoretically even longer. 

So when you combine that concept with the idea of building muscle mass, losing weight and getting into shape you're sure to have a winner.

Actually I'm not so sure that's theoretically true.  As supplements go, I'm sure it probably has many merits on the basis of the value of its ingredients.  However I suspect there's a big difference between a supplement PAC drink and real mothers milk.  Furthermore if mothers milk was so healthy I'm sure someone would found a way to hook a few dozen wetnurse is up to a milking machine to supply some professional wrestlers in Tour de France bicycle racers with all the help they would need to outperform their competitors.

Plus, I've had three children.  I happen to know that all the mothers milk that they drank tended to make them a little pudgy, called baby fat if you will.  That baby fat was rapidly worked office since they started exercising more and eating regular food.  I'm sure the exercise was the biggest part of that, but mothers definitely did not make them muscular.