From a consumer standpoint, most people have brand loyalty. For instance, I'm a diet Mt. Dew drinker. I looked and they do have a substitute, but based on reviews, no one said it tasted anything like the real thing, not even close. That would give me pause from purchasing it. I'd assume loyal drinkers of Coke and Pepsi would feel the same. This will limit their market expansion until the cost differential becomes large enough that people will tolerate the taste difference.For me, I'd explore putting in a refurbished soda fountain and buying the real thing first. I've seen site dedicated to doing this.