230 the system 130 may differently grant a rank to the user using purchasing information of the user in this instance the purchasing information may include a number of times merchandise is purchased by the user that is a number of purchase times or a purchase price specifically the system 130 may differently grant the rank to the user according to the number of purchase times or the purchase price as an example when the number of purchase times of the user is 10 and the number of purchase times of another user is 5 the system 130 may grant a second rank to the user and a third rank to the other user as another example when the purchase price of the user is 100 000 won and the purchase price of the other user is 50 000 won the system 130 may grant a second rank to the user and a third rank to the other user here the number of purchase times may designate a number of times the system 130 lots merchandise by depositing the charge by the user the number of purchase times may be calculated by a predetermined period unit for example the number of purchase times may be calculated in a unit of one month or one year the purchasing price may designate an amount of a charge for one time deposit or a sum of deposit conducted during a predetermined period e g one month or one year as another example for granting the rank when merchandise won through the preceding lottery corresponding to a merchandise information package determined in advance or merchandise having a relatively low winning probability the system 130 may grant a relatively higher rank to the corresponding user for example.