A system platform and associated methods are provided for implementing online reverse auctions in a social network platform (SNP). A fully-automated, live, reverse-auction based system is integrated into an SNP to enable buyers to initiate desired transactions and take advantage of a subscribers' network of friends, colleagues, co-workers, family members and connections by connecting buyers and sellers in a non-intrusive, targeted fashion. Sellers compete for buyers' business by providing dynamic, real-time seller-specific pricing while simultaneously optimizing the seller's target parameters such as price, inventory levels, profit, revenue and volume.