About masternode shares, I think there is a site called Masternode.me which allows you to buy shares of a masternode, and receive dividends out of it. The idea is great, but in my case, I would prefer to own a full masternode and receive full earnings.
The itchy part is about true ownership. How do you "secure" the ownership of a node partition? Falling for a ponzi lures around that corner, too. People selling shares of a node that does not even exist.
Similar to cloud mining. I once owned mining contracts on Poloniex. They had been free tradeable. Poloniex still exists. Those MNS1 (??) shares are gone, I sold before things went south. Payouts would have never ROI'ed anyways.