C2B is a type of e-commerce model where the one side of exchange is consumers and the other side of exchange is businesses. In C2B e-commerce model, they may be two different approaches. In the first approach, consumers may sell its products or services to businesses. In the second approach, the transactions are initiated by consumers. Consumer sends a request to businesses for a product or service and then businesses make a bid. Then, consumer decides where the product or service will be bought from.