Best Buy recently launched WiMax-based 4G through its Best Buy Connect service. The new service offers unlimited use of Clearwire's WiMax network for $45 per month. Access is available month-to-month or via 2-year contract.
Best Buy charges customers $45 per month and pays Clear $30 per month (or whatever they pay) to use their network. And Best Buy worries about the retail/customer service level well Clear worries about maintaining the network.