What is IP Funneling and should I use it in place of 301 redirects?

• We own multiple domains that are not currently in use. We'd like to redirect all of them to point at our main site but we really need to avoid having them get indexed and appear to serve duplicate content. We know that you advise 301 redirects but we've also been told we could use something called IP funneling. Is this something we should consider in place of the 301 redirects?

Answer: The primary objective of the IP funneling process is to eliminate duplicate content — i.e. prevent indexing of multiple Web site domain names that all point to the same content online. IP funneling allows you to point these extra domains to a feeder site (which has an index file, robots.txt file, etc) which in turn forwards to the main site that you're trying to boost in the search results.

The main complaint of this approach (and the reason you don't see it used very often) is it works very much like an off-domain doorway page which really doesn't provide a benefit to the user. In fact, the meta refresh tag on the feeder site sends off a red flag to us (and potentially the search engines as well), which could result in a penalty. This tag makes the page impossible to be seen by an actual visitor — yet provides optimized header content that the spiders can see. The end result is that the visitor clicks through to the feeder site then is immediately redirected to your main site.

Frankly, there just aren't enough real SEO benefits to using this approach and risking an easily avoided penalty. A 301 redirect is the accepted method to use when you want to permanently redirect all your other domain aliases to one main domain. By following the 301 approach you will keep out of trouble with the search engines and still get...