— Derive customer insights (product development as well as marketing and sales).
— Co-create products (product development).
— Leverage social to forecast and monitor (operations and distribution).
— Use social to distribute business processes (operations and distribution).
— Marketing communication / interaction (marketing and sales).
— Generate and foster leads (marketing and sales).
— Social commerce (marketing and sales).
— Provide customer care (customer service).
— Improve intra- or inter-organizational communication and collaboration (enterprise-wide leverage).
— Match talent to tasks (enterprise-wide leverage)
Good summary of David F. Carr the McKinsey Study on Social Economy with 10 top use cases.