Warning: Thread hijack. The issue is postmix vs. premix. Corny kegs held the mixed soda --- if you have ten 5 gallons kegs you had 50 gallons of soda. With the post-mix approach, the bag-in-a-box holds concentrated syrup which is "post-mixed" with carbonated water. Just a much more efficient means of serving soda. (Hey, it's soda here in Indiana, or just "coke").