The process whereby a product or service is made visible to users of the Internet, usually via banner adverts placed on Web pages. Such adverts are often negotiated by an Internet advertising bureau or may form part of an advert auction. The Web site on which the adverts are placed is normally paid a fixed amount when a visitor either clicks on the banner advert to take them to the advertiser's site, or when a purchase is made after the banner advert has been clicked; the amount paid for the former is usually very small. The monitoring of the use of banner adverts and the payment process is often carried out by an intermediary company known as a purchase intermediary or a click intermediary. There are other forms of advertising on the Internet: for example, the use of spam or newsgroups devoted to commercial announcements. However, the bulk of the advertising associated with the Internet is that associated with banner adverts.