A pop-up display is a small window that opens up on top of another browser window. Normally, pop-up displays are related to some form of advertising, either for a product or another website. However, pop-up displays can also alert the user to an error or other type of notice related to his or her personal computer operating system.
Pop-up displays usually cover part of the window on which the user is working. Many advertising pop-up displays feature false “close” buttons, which, when activated, open up yet another pop-up display or even an entirely new advertising window. Advertisers sometimes use this method to “trap” the user, and some of the sites they link to are nearly impossible to exit. Some advertisers also use what is called a pop-under display – that is, a new window that opens up underneath the active window. Pop-under displays are less bothersome that pop-up displays, but because they are only detected once the user closes the browser window, they can remain open for much longer and are difficult to trace.
Pop-up displays are created using JavaScript and are most often generated by the owner of the website the user is visiting. Pop-up displays can also be the result of some type of adware software that has been installed on the user’s computer, either by choice or surreptitiously. In the early days of the Internet, webmasters used embedded banner ads to generate revenue to support their sites. However, as computer users became savvier and began ignoring these banners, advertisers began paying less for click-throughs and revenues dropped. Pop-up displays were a natural progression from banner ads, and they can still be a lucrative source of revenue.
Almost as soon as pop-up displays began appearing on computer screens, enterprising software engineers began developing tools designed to block them. Early on, several major browsers, including Opera and Mozilla, were able to totally block pop-up displays for their users. Ultimately, every major browser, with the exception of Internet Explorer, had this technology in place. Finally, in 2004, Microsoft incorporated a pop-up blocker for Windows XP that, if activated, effectively blocks pop-up displays for users of Internet Explorer. Still, many computer users find that pop-up blockers interfere with normal usage and often turn off the blocker when visiting certain websites.