Moving document and file locations on the web is fairly common. So what do you do when you have to communicate the move to your users and the search engines? You set up a redirect.
There is no question that search engines prefer to see a 301 redirect. But just to make it clear, I wanted to quote a fresh friend where John Mueller, a Google Webmaster Trends Analyst, says once more that a 301 redirect is preferred. In fact, a Google Groups thread goes as far as saying that a meta refresh redirect may be used by some search engines as a spam red flag prompt. I am not sure if that is the case with Google, but John does comment on it.
I touched on meta refresh type redirects back in my posting on meta tags at WBC Blog. In general, we go not recommend using this kind of redirect. If you need to redirect users to a page, it is preferred to use a clean server side redirect.
John then adds his personal thoughts:
As Silverstall mentioned, some search engines (AltaVista is mentioned in that article) have seen meta refresh type redirects with a short time to redirect as a spam-signal. Personally, I find the longer time periods problematic as well, at least for the user. Who expects to be redirected to a different page after 30 seconds? It's just confusing :-).
Why would someone think a search engine would use a meta redirect as a spam technique? It could be used for showing one piece of content to a search engine and a different piece of content to the end user, a form of cloaking can be applied to it.
Forum discussion at Google Groups.