It's certainly OK in principle. What you need to do is make sure that the redirect generates a 301 server header when it sends traffic to the core domain.

In terms of "how many", the answer may not be straightforward. I know of a coroporation who owns and redirects over 1200 domains to their core domain. Many they own for trademark protection, keeping typo-squatters at bay and so on. Others they own because they acquired the businesses and folded them into their core operation.

However, I feel it is important NOT to continue to promote, link build, etc for those domains that now redirect. That can be seen as a kind of ranking manipulation and the penalty can be harsh.

Thanks for the helpful tip, tedster.

Well I use Godaddy's domain forwarding feature. How can I tell if I have done the redirection accurately? You said " make sure that the redirect generates a 301 server header when it sends traffic to the core domain" What exactly do you mean?

Thanks

Whenever a request is made from your server, the first thing it sends out is the http header and that includes a numeric status code - see this W3C reference for all the status codes [w3.org]. If you are redirecting the original address that the user requested, there are a few choices for that redirect status, and the one you need to be using is a 301.

To check the server header I use a Firefcx add-on called "Live HTTP Headers" - and there are lots of utilities around the web that will check it for you, too.

In terms of "how many", the answer may not be straightforward.

there is a Matt Cutts video about this, and he mentions that google.com has numerous forwards. Many of them use the word google in all sorts of permutations like the word google + (your favorite adult content term here).com

Of course, what is for google may not necessarily work for everyone else, but the implication I got from the video is if all you are doing is making sure that you are getting common misspellings of your domain name, or registering multiple TLDs of your domain name, then it should be fine.

Of course, you will want to reference that exact video to be sure about that.

I had linked to the video in this thread...

WMT Suggests More Sites I Should Add to my Account
http://www.webmasterworld.com/google/4225837.htm [webmasterworld.com]

The video is excellent. Matt doesn't explicitly touch on a key point which tedster makes, though, important enough in the context of this discussion that it's worth repeating....

I feel it is important NOT to continue to promote, link build, etc for those domains that now redirect. That can be seen as a kind of ranking manipulation and the penalty can be harsh.

I'd go so far as to say that you don't want to redirect too many previously promoted domains to your core domain. There's no problem with unpromoted domains for type-ins, brand protection, etc.

Also, make sure that your redirected domains return 301 header responses, not 302 or 200 responses, which can easily happen. These latter two can cause dupe content problems.

You said "make sure that the redirect generates a 301 server header when it sends traffic to the core domain" What exactly do you mean?

I've always felt that the W3C standards documents are very difficult reading for anyone who doesn't know what an http header is. Ditto with Wikipedia.

One of the most complete and easily digestible introductory discussions I've found of HTTP headers is this article, dated but clear to a non-technical reader...

How the web works: HTTP and CGI explained
http://www.garshol.priv.no/download/text/http-tut.html [garshol.priv.no]

Headers are discussed in the "Server response" section. I would read it through from the beginning. (Again, other sections of the article are dated, as it's from 12 years ago.)

Thanks for the link to the addon Tedster, can you tell me if this is normal. I tried it and went to my .ca which is pointed at my .com
I see two 301's , once to direct to the dot com , then another to the www. I use htaccess to handle the canonical issue to the www.
Shouldn't the server have just pointed to the www version instead of the non www saving me the extra 301 which might look odd to google ?

It is "normal" - not ideal but not really a problem, either.

If you were totally in control rather than GoDaddy, the ideal would be to 301 redirect both versions (with and without the "www") directly to the "www" version of the core domain. Redirect chains, even for canonical purposes, are not ideal for transferring maximum backlink power.

However, your current scenario is so common that, as I said, you don't have a real problem.

@Robert Charlton:

I'd go so far as to say that you don't want to redirect too many previously promoted domains to your core domain. There's no problem with unpromoted domains for type-ins, brand protection, etc.

One implication of what you are saying then is that it is a BAD idea for people to go around buying up expired domains (or soon-to-be expired domains) and redirecting them to one site in order to "harvest" the incoming links to those expired domains, correct?

...a BAD idea for people to go around buying up expired domains (or soon-to-be expired domains) and redirecting them to one site in order to "harvest" the incoming links...

This, IMO, is why Matt in the video artfully avoided mentioning certain aspects of redirection... and it's also what made my answering your earlier question tricky. I didn't want to bring it up either.

Google would certainly view this and similar uses of redirection as manipulation rather than as a natural sign of quality, and it's a technique I wouldn't use to boost a domain I valued. I know that Google has tools that can detect this kind of redirection... but I don't know whether they can apply it on system-wide basis. Redirected links are harder for competitors to spot. I haven't checked out how various link data bases report 301s.

Over the years, I've seen the technique used for various purposes that I'd call unethical, not just spammy... and it is something that Google will treat harshly.

I should add, btw, that buying up new keyword domains and 301ing them to a main site with expectations that the keywords alone in the redirected domains will boost rankings is up there with meta keywords and the tooth fairy. As soon as a domain is 301ed, the keywords in the domain are gone.

What may be left after such redirects are any anchor text links still in place to the keyword-rich domain that's been redirected. It seems to me though, particularly in situations where you control the sources of inbound links in the first place, that its pointless to go through the charade of putting up a domain only to redirect it. Just put up the spammy link.

The slap from Google is also likely to be a lot harder for hidden redirects than for simple spammy anchor text links to the main site, though scale and frequency of transgression also enters into this.

I agree with Robert with one qualification. If you buy a whole business and not just a domain, and you fold that business into your already existing website, then it's natural to use the 301 redirect to preserve previous backlinks, and it's also totally acceptable to Google.

If you buy a whole business and not just a domain....

tedster - I of course agree with that qualification, and perhaps should add another qualification as an amusing side note. I'd said that "you don't want to redirect too many previously promoted domains to your core domain", but "too many" may be relative to who you are.

I realized a while back as I was cleaning up some old bookmarks that you could almost trace the history of various business niches by following the redirects. Many small companies are absorbed by medium-sized companies, and many medium-sized companies are absorbed by the large ones. It was fascinating to see (and I won't mention specifics) what companies were on the receiving end of a bunch of redirects.

Been busy, belated thanks Tedster

I once 301'd a number of mini sites to one main site to consolidate the mini's and focus on a quality site,,

2 months latter, the main site's SERPs had been nuked to the stone age, everywhere

wish i had seen this thread then, before doing that