A company to manufacture its products requires raw material, labor etc.This creats a buyer-supplier relationship in an industry.If there are few suppliers providing material essential to make a product then they can set the price high to capture more profit. Take a look at the PC industry, it faces a monoplistic power of an operating system supplier. Yes you guessed it right Microsoft. Go to purchase a Dell, Toshiba or HP's laptop it will come with Windows Vista. PCs have to be compatible with Windows platform.On the other hand if there are lot of suppliers competing for few buyers, then the buyers take control of the price. Walmart has a monoploy over its suppliers. If your product is not in Walmart, then you are out of business. To give its customers a better buy, Walmart can control the prices of the suppliers.