Marketing managers in television work with a relatively stable advertising medium. In many ways, television advertisements aired today are similar to those aired a few decades ago. Most television ads still feature television and film actors and still show a product, however, the differing dynamics of the Internet pose distinctive challenges to advertisers, forcing them to transform their practices and methods on regular basis. In the early days of Internet marketing, online advertisers employed banner and pop-up ads to attract consumers. These practices reached large audiences, generated many sales leads, and came at a low cost. Though, a small number of Internet users began to believe these advertising techniques disturbing and irritating. Marketing tactics rely heavily on streamers and pop-ups produced results, companies invested growing amounts of money into purchasing these ads in the hope of capturing market share in the mushrooming online economy. As consumers became more urbane, frustration with these online advertising techniques grew. Independent programmers began to develop tools that blocked banner and pop-up ads. The backlash against banner advertisements grew as new web browsers provided customers the ability to block image-based ads such as banner ads. Although banner and pop-up advertisements still exist, they are far less important than during the early days of the Internet. A major expansion in online marketing came with the introduction of pay-per-click ads. Unlike banner or pop-up ads, which initially required companies to pay every time a website visitor saw an ad, pay-per-click ads allowed companies to pay only when an interested prospective customer clicked on an ad. More importantly, however, these ads bypass the pop-up and banner blockers.