Interesting aside. Back on topic: the homes were not granted to Zuckerberg; and his residents are not serfs. So they are not "perfectly comparable," they are barely comparable.
(not to mention serfs could not be bought alone, they could be sold with the land. Maybe you are thinking of slaves?)
He purchased the homes in a free market, they were not granted to him; the residents are not serfs.
So I guess it's like feudalism in that...there's a landlord?