I don't understand how a tweet qualifies either. I think it started out with trading cards and card games like splinterlands. You own a card or a token. In this case, it usable as an enhancement to the game. From what I've read, you can buy a tweet but, you don't own it but rather a "token" that represents that tweet and holds a perceived value.
If someone wants to buy my utterances on twitter, so be it.