Well, he could try to actually make it a usable platform and offer features people might be willing to pay for?
Think about it, this blue checkmark subscription would have absolutely worked two years ago. You have to prove who you are, pay 10 bucks a month and then you'll get the checkmark. A lot of people and institutions would have done that.
Offering advanced, paid features for professionals might also help. Like user management or thread based user mappings, so that large accounts can get management by a team efficiently. Companies are definitely willing to pay substantial amounts of money for things like that.