Online advertising, also called Internet advertising, uses the Internet to deliver promotional marketing messages to consumers. It includes email marketing, search engine marketing, social media marketing, many types of display advertising (including web banner advertising), and mobile advertising. Like other advertising media, online advertising frequently involves both a publisher, who integrates advertisements into its online content, and an advertiser, who provides the advertisements to be displayed on the publisher’s content. Other potential participants include advertising agencies who help generate and place the ad copy, an ad server who technologically delivers the ad and tracks statistics, and advertising affiliates who do independent promotional work for the advertiser.
Online advertising is a big business and growing rapidly. In 2011, Internet advertising revenues in the United States surpassed those of cable television and nearly exceeded those of broadcast television. In 2012, Internet advertising revenues in the United States totaled $36.57 billion, a 15.2% increase over the $31.74 billion in revenues in 2011. Online advertising is widely used across virtually all industry sectors.
Despite its popularity, many common online advertising practices are controversial and increasingly subject to regulation. Furthermore, online ad revenues may not adequately replace other publishers’ revenue streams. Declining ad revenue has led some publishers to hide their content behind paywalls.