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A variation on the pop-up window is the pop-under advertisement, which opens a new browser window hidden under the active window. Pop-unders do not interrupt the user immediately and are not seen until the covering window is closed, making it more difficult to determine which web site opened them.
Pop-up blocking 
Opera was the first major browser to incorporate tools to block pop-up ads; the Mozilla browser later improved on this by blocking only pop-ups generated as the page loads. In the early 2000s (decade), all major web browsers except Internet Explorer allowed the user to block unwanted pop-ups almost completely. In 2004, Microsoft released Windows XP SP2, which added pop-up blocking to Internet Explorer.
Most modern browsers come with pop-up blocking tools; third-party tools tend to include other features such as ad filtering.
- Certain types of downloaded content, such as images, free music, and others, can cause pop ups, and therefore should not be trusted. Especially pornographic sites' pop ups (known as a "pornado" or "porn-storm", as coined by John C. Dvorak.) Also, the pop ups will sometimes look like ordinary web pages, and the name of the site will show up in a search bar. Many websites use pop-ups to display information without disrupting the page currently open. For example, if you were to fill in a form on a web page and needed extra guidance, a pop-up would give you extra information without causing loss of any information already entered into the form. Most pop-up blockers will allow this kind of pop-up. However, some will reload the page, causing loss of any information that had been entered.
- Some web based installers, such as that used by McAfee, use a pop-up to install software.
- On many internet browsers, holding down the ctrl key while clicking a link will allow it to bypass the popup filter.
- Clicking (even accidentally) on one pop-up may lead to other pop-up ads opening.
Circumventing pop-up blocker 
Pop-under ads 
Pop-under ads are similar to pop-up ads, but the ad window appears hidden behind the main browser window rather than superimposed in front of it. As pop-up ads became widespread and took up whole computer screens, many users learned to immediately close the popup ads that appeared over a site without looking at them. Pop-under ads do not immediately impede a user's ability to view the site content, and thus usually remain unnoticed until the main browser window is closed or minimized, leaving the user's attention free for the advertisement.
Pop-under ad technology 
// create a new window in front of the current site window.open( URL, windowName[, windowFeatures] ); // push the loaded advertisement back behind the browser window.focus();
Most modern browsers allow window.open to be executed only if it was called as a result of a user interaction (e.g. mouse click) event handler. Any non-interactive calls (timer callback, load events, etc.) to window.open will result the new window being blocked. To bypass this restriction, most pop-under ads are triggered by a mouse click event listener attached directly to the document or the document's body. This enables catching all mouse clicks events that were not consumed by other click event handlers, and calling window.open without being blocked. For example, when the user selects a text, the mouse click triggers the mouse click handler attached to the document and a pop-under pops using the above code. Notice that there are more techniques to bypass the window.open call restriction by "hijacking" mouse clicks.
Circumventing pop-under blocker 
"Poper Blocker" is a Chrome extension dedicated to block pop-unders that use various techniques to bypass the window.open call restriction as described above.
Pop-up dismissal 
Users of websites and web applications continuously experience unwanted pop up ads through the course of their normal interaction with a web browser. Ordinarily users respond by dismissing the pop-up through the "close" or "cancel" feature of the window hosting the pop-up. Because this is a typical response, some authors of pop-up advertising depend on this, and create on-screen buttons or controls that look similar to a "close" or "cancel" option. When the user chooses one of these "simulated cancel" options, however, the button performs an unexpected or unauthorized action (such as opening a new pop-up, or running unauthorized commands on the user's system).
Because the technologies for web development and design allow an author to draw any kind of "simulated" cancel option imaginable, some users refuse to click on or interact with any item inside a pop-up window whatsoever.
Patent controversy 
See also 
- Ad filtering
- Ad serving
- Adware and Spyware
- Direct marketing
- Interstitial webpage
- Lawsuit between 1-800 Contacts and WhenU SaveNow over pop-up ad placement
- Messaging spam
- List of pop-up blocking software
- In-session phishing
- Adams, Cecil. "What's up with popup ads?". The Straight Dope. October 15, 2004.
- Zabunov, S. "From Annoyance to Pleasure - The Artistic Popup Approach". May 12, 2006.
- US Patent 7,386,555 "Post-session internet advertising system"
- US Patent 7,353,229 "Post-session internet advertising system"
|Look up pop-up advertisement in Wiktionary, the free dictionary.|
- How To Stop Internet Popups - entry in wikiHow
- Pop-under ads may hit publisher wallets
- IAB Pop-Up Guidelines and Best Practice
- "Poper Blocker" - The first pop-under blocker for Google Chrome