Popup Ad

Pop-up ads are a form of online advertising on the world wide web intended to increase web traffic or capture email addresses. It works when certain web sites open a new web browser window to display advertisements. The pop-up window containing an advertisement is usually generated by JavaScript, but can be generated by other means as well.

A variation on the pop-up window is the pop-under advertisement. This opens a new browser window, behind the active window. Pop-unders interrupt the user less, but are not seen until the desired windows are closed, making it more difficult for the user to determine which web site opened them.

PopUp Ads: Overview

For early advertising-supported web sites, banner ads were sufficient revenue generators, but in the wake of the dot com crash, prices paid for banner advertising clickthroughs decreased and many vendors began to investigate more effective advertising methods. Pop-up ads by their nature are difficult to ignore or overlook, and are claimed to be more effective than static banner ads. Pop-ups have a much higher click rate than web banner ads do; it's estimated that about every 14000th popup ad is clicked on.

Opera was the first major browser to incorporate popup-blocking tools; the Mozilla browser later improved on this by blocking only popups generated as the page loads. In the early 2000s, all major web browsers except Internet Explorer (then the most popular browser and still as of 2004) allowed the user to block unwanted pop-ups almost completely.

Session Hijacking and Mousetrapping

Pornographic web sites are among the most common users of pop-up ads. Some particularly vicious types of pop-up ads (again, most often seen in connection with adult entertainment sites) appear to have either been programmed improperly or have been specifically designed to "hijack" a user's Internet session. These forms of pop-ups sometimes spawn multiple windows, and as each window is closed by the user it activates code that spawns another window -- sometimes indefinitely. This is sometimes referred to by users as a "Java trap", "spam cascade" or "Pop-up Hell" among other names. Usually the only way to stop this is to close the browser.

Another variation of pop-up, commonly called "mousetrapping", particularly fills an entire screen with an ad or web page, in the process removing any menu bars or other on-screen icons by which the user can close the window. This problem mainly affects users of the Windows version of Internet Explorer. Often, access to other open windows and web pages is denied and the only way for PC users to close these ad windows is via the control-alt-delete command, which can result in all active IE windows (including those not connected to the pop-up) closing.

Non-browser PopUp ads

Processes other than the web browser can also display pop-up ads, or can direct the browser to display them. Many spyware programs do this, as well as some advertising-supported software, although the line between the two is sometimes thin.

A different sort of pop-up ad can be sent via the Messenger service in Microsoft's Windows operating system. These pop-ups appear as Windows dialog boxes with a textual message inside, usually directing the user to a web site.

This article is adapted from: wikiPedia.com.