But I'm not sure if anyone still cares about Klout scores. I'm not sure if they ever did, except for fun.
Any such score, used to deny service to group x based on parameters unrelated to the product itself would simply be discrimination, no?
With that out of the way in small businesses reputation can matter quite a lot. Informally many small businesses know that one guy/shop/service that is not worth having as a client. Regardless of discriminatory issues every client has varying levels of cost associated to doing business with them. So just like Credit Scores are a risk profile for how a person will handle debt. You could envision a subset of social scores as a risk profile on having someone as a business partner/client/provider based on metrics like support cost, likelihood of nickle and diming you, Contract negotiations gone wrong. That sort of thing.