Problems with Using Meta Redirects
Internet Explorer 8 recognizes this code and redirects a visitor to a new site after a pre-defined number of seconds. However, there are a few problems with using Meta redirects.
Search engines such as Google, Yahoo, and Microsoft Bing may interpret redirects as an attempt to garner more favor with the search engines than is warranted by the content of a page. Some black hat search engine optimization (SEO) techniques include putting one page up to rank well with the search engines and then redirecting visitors to another page or website.
You may not be engaged in any black hat SEO behavior, but by allowing IE8 to initiate the redirect, the bots that crawl the web for the search engines will not be able to tell the difference between honest and dishonest attempts to rank well. Meta Redirects also do not allow the “back" button on browsers to work because every time a user of IE8 presses the back button, the Meta Redirect will just keep redirecting to the new URL.
The World Wide Web Consortium has this to say about Meta Redirect:
“Imagine that the user presses the "back" button, the refresh would work again, and the user would bounce forward. The user will most likely get very annoyed, and close the window, which is probably not what you, as the author of this page, want." http://www.w3.org/QA/Tips/reback
This is especially true for black hat web designers who use a value of zero for the Content variable. There are a host of other ways to redirect users to a new site without appearing to be using black hat SEO techniques but the most useful are what are known as HTTP 301 and HTTP 307 Redirects.