The present invention refers to method relates to a is allocated real estate type sale, homepage step of a publisher information building sale; said an operator homepage Internet terminal a contractor is building sale after selecting the piggy bank in a phone recognizes contract deposit sale to deposit accounts that the account is is opened conveys incoming coins contractor from a server of a designated bank by setting a sale is generating written contract , in certification authority electronic signature verifies it by public key infrastructure is provided to the contractor is generated from utilities in written contract conditional refund after receipt of the electronic signature to a contract sale in the form a ball particulars to main screen of sale and; ball rate sale designated bank from a server of said server conveys incoming coins contract deposit sale to receive a digital sound source information to portable information terminal in real total sale receipt includes contrast contract deposit sale total of article and the utilities contract deposit calculated according to the proportion of ball a utilities rate; and said predetermined according to an operator homepage sale conditions utilities period has terminated, the final sale rate is matched with a preset reference sale rate exceeds a conditional refund said effective to a contract form for treatment of the contract and engaged, reference sale rate fall below at contract for form conditional refund said surface so to be while processing of bank designated via a server said utilities receipt includes a refund to contractor is contract depositit included[...] characterized in that comprises.