"If God exists, it no longer matters what you believe is right and wrong."

Why don't they sell milkshakes in gallon jugs? They sell yogurt that you drink, smoothie drinks, etc. Why not milkshakes? I would love to keep a gallon of low-fat, skim-milk milkshake in my fridge at work. High-protein energy for a man who loves milkshakes. That could be the slogan! Why doesn't this already exist?