A system and method for allocating conditional purchase offers (CPO) among a plurality of agency-based and broadcast-based sellers in a buyer-driven commerce system. In one embodiment, the system determines which agency-based or broadcast-based sellers can fulfill or satisfy the CPO and orders those sellers in a priority order. In another embodiment, the priority is determined by relative market share and number of recent opportunities to satisfy the CPO. In another embodiment, the priority is also determined by metrics and buyer information. In another embodiment, the priority is determined randomly. The system ensures that when a buyer can satisfy the CPO at multiple prices levels, the highest price level fulfills the CPO. This ensures maximum seller revenue for each CPO.