1. A method of selling commodities and sharing sales profits, in which an Internet managing system of a commodity seller for electronic commerce is connected to terminals of both at least one commodity purchaser and the commodity seller to sell commodities and to share sales profits obtained from sold commodities to the commodity purchaser, comprising: accessing the Internet managing system of the commodity seller through the Internet by the commodity purchaser, to apply for member subscription and enter a desired deposit amount corresponding to an anticipated amount to be spent purchasing commodities for a predetermined period, with reference to various stipulations and information related to member subscription and deposits guided through a home page provided by the commodity seller; approving member subscription of the commodity purchaser by the Internet managing system of the commodity seller, by examining qualifications thereof through the Internet, informing the commodity purchaser of approval of the member subscription in real time through a mail server, requesting the commodity purchaser to give the desired deposit amount as a deposit, and automatically transferring the deposit to an account of the commodity seller; accessing the Internet managing system by the commodity purchaser, to purchase commodities provided by the commodity seller for a predetermined stipulated period; and issuing to the commodity purchaser by the Internet managing system of the commodity seller, a dividend of sales profits corresponding to a predetermined dividend rate according to purchase of commodities on the basis of a smaller one of an actual amount spent purchasing commodities and an anticipated amount to be spent purchasing commodities, as a refund, after the stipulated period initially set by the commodity purchaser through the Internet has elapsed, and issuing to the commodity purchaser an award for contribution corresponding to a predetermined coverage ratio of a difference between the actual amount spent purchasing commodities and the anticipated amount to be spent purchasing commodities with respect to the difference.