Direct selling is an ancient art. It basically goes on to understand the customer and create such a relationship with him that it transforms into a sale of the product. The beauty you must understand is in forging a relationship.
It is like someone comes up to you and becomes very friendly with you. He offers you a cup of coffee and there you have it, he has actually sold you the coffee cup and yet you both have coffee every time he comes knocking on your door.
You must understand that advertising is essentially a pull strategy. That is, the customer having seen the advertisement is pulled to the retail outlet. But direct selling is a push activity. That is, it reaches the customer and seals the deal.