Milkshare is an open milk donation system. The milk is basicly shared mother-to-mother vs being sent to a milk bank where it is tested, batched, pasteurized, and tested again before making it's way to babies (and even adults!) in dire need of human milk.
Mothers who are able to pump A LOT of milk to send often are dealing with overproduction issues (meaning they are making milk well in excess of their baby's needs). Most mothers would not be able to send an extra 100 ounces of milk per week.
Exactly. Here's a post I recently wrote on this topic: