You can't completely pigeonhole Skype when it serves both as a partial substitute for traditional phone service and an instant messaging service with voice and video on top.
Electric and natural gas utilities that provide partial (or full) service to consumers are heavily regulated by government agencies, which set the price utilities charge customers for electric and gas service, the terms of that service, capital budgets and construction plans and so forth.
People were duped into sending a partial or full payment to a third-party agent via a wire transfer payment service and to fax their payment receipt to the seller as proof of payment.