But why would anyone else want to buy your Steem? I still don't understand how it has any value unless someone else is willing to pay for it, and don't say "investment opportunity" because that sounds like one big ass Ponzi scheme to me.

But, perhaps you are right, and businesses will want to tip the scales in their favor by scooping up as much Steem Power as possible so their content stays at the top. If that becomes reality, and businesses end up purchasing a lot of Steem Power, then don't you think the Steem community will just become one big billboard? Users will leave. I don't see the benefit in having a community where everyone's voting power isn't equal. In fact, that sounds a hell of a lot like a Aristocracy, doesn't it? Humanity tried that before, it didn't work.