an information offering method including : disclosing summary information about a designated product via a designated communication line ; judging whether or not the user reading said summary information disclosed by said summary information disclosing step and desiring to read detailed product information about the product about which said summary information is disclosed is a user who is permitted to read detailed information ; and disclosing detailed information about the product about which said summary information is disclosed , to the user who is judged to be permitted to read detailed information by said judgment step .