Pop-up ad

Form of online advertising Example of an in-page pop-up ad Pop-up ads or pop-ups are forms of online advertising on the World Wide Web. A pop-up is a graphical user interface (GUI) display area, usually a small window, that suddenly appears ("pops up") in the foreground of the visual interface. The pop-up window containing an advertisement is usually generated by JavaScript that uses cross-site scripting (XSS), sometimes with a secondary payload that uses Adobe Flash. They can also be generated by other vulnerabilities/security holes in browser security. A variation on the pop-up window, the pop-under advertisement, opens a new browser window under the active window. Pop-unders do not interrupt the user immediately but appear when the user closes the covering window, making it more challenging to determine which website created them. History Pop-up ads originated on the Tripod.com webpage hosting site in the late 1990s. JavaScript provided the capability for a web page to open another window. Ethan Zuckerman claims he used that capability to launch advertisements in separate windows as a response to complaints from advertisers about their ads appearing on pages with sexual content.