Advertising revenue is at the heart of many Internet services, but numerous questions are being raised about the effectiveness of static advertising on a web site. The objective of many commercial WWW sites is to bring eyes to advertising in order to support the continuation of their service. Merely creating a web site and then hoping people will visit is passive and ineffective. Making sure that customers come back to a site is critical to advertisers and, therefore, to sites trying to generate revenue from the sale of services and products. Not surprisingly, the language of push publishers is strongly influenced by television and radio.
Users continue to subscribe to the service if they value the information sent to their mailboxes.
For example, Mercury Mail gathers information from a variety of news sources, then customizes the information for the user. It delivers the information free to the user and generates revenue by attaching advertising to the messages. Since the content is highly targeted to the interests of the subscriber, the advertising can be similarly targeted. For instance, individuals will accept a special offer from a ski manufacturer or resort attached to a daily snow-conditions service. Personalized news delivery services have been in operation since the 1980s.