Kinda similar point to my "a place to spend your money - or earn it"

Investors will come in bulk to easy to conceptualize stuff, if people are buying water at a concert the investor buys more water. if it's beer, he calls that guy instead. If it's nothing, he goes and invests in movie theaters instead.

He never cares how the water filters or kegs work, only what people are buying or selling a lot of.