SO is a social media site. So I think it makes more sense for a company like LinkedIn, Facebook or Condé Nast.

LinkedIn is making bank with its subscription tiers. So they’d do a good job, financially speaking, of doing the same thing with SO. Large companies and recruitment services will be able to buy premium subscriptions to see who is doing what on the platform. Professionals will pay $50/month to have better access and limit access to non-paying members.

EDIT: Oops. Now I know that Microsoft owns LinkedIn.