Abstract: A network server for providing web pages to user terminals which access through user identifications (IDs) may include: a communicator connected to a network; and a processor configured to communicate with the user terminals through the communicator. The processor may be configured to score first convertibility points corresponding to the respective user IDs, according to whether actions of the user terminals on the web pages are matched with predetermined user events, select one of the plurality of message types according to whether the first convertibility point of one user ID among the user IDs is higher than a threshold value, when the one user ID accesses through a user terminal, and provide the selected message type including the selected object to the user terminal of the one user ID.