The typical industry approach is [retailers] to treat vendors like the enemy... If vendors can't make a profit then they don't have money to invest in research and development, which in turn means that the products they bring to the market will be less inspiring to customers, which in turn detriments the retailer's business because customers aren't inspired to buy. People want to cut costs and negotiate aggressively because there's a limited amount of profit to be shared by both sides. As a result of this "death spiral", most retailers fail.
