An online shopping support method and system capable of supplying proper services matching user specific needs and conditions. Purchase history information of each good purchased by each user is stored at a service offering system. In response to an input of identification information from a service use system, the service offering system searches the purchase history information of the user corresponding to a user identifier and calculates a purchase interval of each good purchased by the user. The service offering system judges, for each good whose purchase interval was calculated, whether the time corresponding to the purchase interval has lapsed after the latest purchase day. The service offering system transmits information of the good whose time corresponding to the purchase interval has lapsed to the service use system via a communication network and displaying the information at the service use system.