An annoying misfeature of many websites.  

HTML provides the capability of redirecting a browser to another page; which is useful for many reasons--such as making the public interface the page (the URL) decoupled from the actual location (there are better ways to do this, of course).  Redirection can include a "delay"; it is a common idiom for a page which has moved to say:

 This page has moved to http:://www.newurl.com.  Your browser will redirect you there 
 in 5 seconds.

The user can then wait the 5 seconds, or if impatient can click on the link to go directly.  This is a useful idiom, and does not violate users' expectations.

However, some websites use the redirect feature with a delay of zero; and no readable content on the page--in other words, the user is ''silently'' redirected to the new page, without warning.  This can violate user's expectations.

Worse, it causes the "back" button to not function correctly (a smarter "back" button might help).  If the user is on the "to" page and presses back, he goes back one step to the "from" page, which then dumps him back on the "to" page.  The user has to use the history list (or enter a new URL) to get out of the site.  Which is a minor annoyance.

In some cases, this is done to deliberately disable the back button; so that the user spends a little additional time viewing the ads.  (It may even generate an additional PageHit, increasing ad revenue).

Browsing software could improve the problem by:

* Redirects with a delay of less than a second (or maybe all redirects) are intercepted by the browser, and a dialog box is displayed informing the user of the redirect and asking to confirm.

* Pressing "back" skips pages with redirects.

* Pressing "back" disables the redirect, presenting it in some out-of-band manner