Disclosed are an auction method and system, an advertising method and system, and a charging method and system, based on a bid price depending on clicks or exposures, and a fixed unit price depending on a time period. The advertising method may include verifying an advertisement exposure priority determined with respect to an advertisement of an advertiser, based on a bid price per click (or a bid price per exposure) which may be input from the advertiser, and exposing the advertisement of the advertiser through an advertisement exposure region depending on the verified advertisement exposure priority, during a time period corresponding to a period-based flat rate unit price determined through an administrator system, wherein an advertising fee depending on the exposure of the advertisement may be calculated based on the bid price per click (or the bid price per exposure), a number of clicks (or a number of exposures) which may actually occur with respect to the advertisement during the time period, and the period-based flat rate unit price.