System for giving entertainment element in return for watching advertisement

A computer system comprising:

• at least one processor or circuit programmed to:
• manage, during progress of a game, user management data of a user of the game, the user management data including data on possessed items possessed by the user;
• provide an input element option presenting menu that displays a plurality of different input elements to be converted by watching an advertisement, wherein each input element of the different input elements is from a plurality of pieces of disposable information, possessed by the user, related to the game, wherein the plurality of different input elements is based on possessed items currently possessed by the user as indicated in the user management data for the user;
• receive a user input operation from the user that selects an input element among the displayed input elements;
• perform watching control for displaying, on a display screen for user operations, an advertisement and perform conversion of the selected input element into an output element that is the disposable information different from the input element in return for watching the advertisement among a plurality of advertisements, wherein the conversion follows pre-defined conversion defining data, the pre-defined conversion defining data being pre-defined as associated with the advertisement, the pre-defined conversion defining data defining (a) a type of the input element, (b) a quantity of the input element, (c) a date/time of watching the advertisement, (d) a quantity of the output element, and (e) a type of the output element, wherein one or more of (a) to (e) can be different for different advertisements;
• and
• give the output element to the user when watching of the advertisement satisfies a completion equivalent condition.