If you have multiple domain names pointing at the same content, then the best choice is to 301 redirect them to whatever your preferred choice of domain is. This will ensure that type-ins still get to see your site and avoid duplicate content penalties with search engines. It should also help to keep the benefit from links whch may be pointing at secondary domain names.If you are using your registrar's forwarding service you should check that they are indeed using a 301 using a server header checkerAs an aside, Yahoo continues to have difficulties properly following 301s but I think this is a side issue as a 301 as the correct method and Yahoo will surely fix this at some point.>>What are the implications/characteristics of the 200 status?If you return a 200 (OK) status to www.primarydomain.com and also www.secondarydomain.com then you are giving the message that they are two separate sites. If the content on each is the same then you risk a duplicate content penalty.>>Google might not like it if you have a lot of domains all pointed to the same domain. I'm talking about no mirrors, everything resolving to one url on the main domainI personally have not seen any evidence for this. If you 301 the domains then your are saying that there is only one site, with more than one domain name. This is as Google would want if you ask me.>>But, would you not also be in trouble if competitors linked to your domains that were pointed via 301s?IMO they'd be doing you a favour! Just hope they use some nice anchor text ;)>>Since spiders don't index 302 redirects, there shouldn't be the same problem.But then you don't get (all of?) the benefit of links to secondary domains. 302 is a confusing type of redirect for search engine, since if the redirect is temporary, how is it to know which page to index? A site of a client of mine has 14 domains pointing at his main domain, w/o 301. This main domain doesn't rank as well as I would have expected for some important keywords. Until now I can't find out why.After reading this thread here I investigated those secondary domains of my clients and ... bingo! At least 3 of them have inbound links from the same 2 sites (link farms). They link not only to those secondary domains but also to the main domain ...These links were made before I started to work for him, as he told me.Following the advice in this thread I will redirect all secondary domains by using 301 moved permanently.How long may it take before they disappear from Googles index?And what else should I do?
Why do engines care? - In order to make a search more relevant to a user, search engines use a filter that removes the duplicate content pages from the search results, Another is that they don’t want to spend the resources in indexing pages that are substantially similar.
That said, there still seems to be some confusion out in the SEO world over ‘duplicate content’ and how search engines treat and deal with them. Right away I would like to say - RELAX -. If you are doing sneaky things like filling up a site with dodgy content that YOU KNOW is duplicate, then worry. Most people that may have duplicate content issues are honest web site owners and aren’t at risk of any penalization.
Is it really a Penalty?
That is the crux of the main misconceptions. Generally speaking it is a ‘duplicate content filter’ not a ‘penalty’ per se, as many in the SEO world seem to agonize over. At various points in the indexation and retrieval process, various documents (web pages) are scored and ultimately removed from the results for a given query.Certainly, if one satisfies other ‘spam’ factors or has an entire site of duplication (aggregate) then it can certainly migrate into a penalty. As I said, for the average website owner you shouldn’t have to worry about penalties, most that migrate to this ground, know the path they are on. Penalties can also be incurred for what is known as a "mirror" - the penalty for a site that is more or less substantially duplicating another single site.How does it work
When a search engine robot crawls the web it reads the pages and stores the information within its database. At various stages of the indexing and retrieval process, it checks the document against the existing index(es) for potential duplication issues. It is scored on a variety of factors including descriptions, authority, document age, content structuring (phrase scoring) and more
For example when Google uses Phrasing to determine duplications one method is outlined below;
When the user (searcher), queries the index it then attempts to further filter out any possible duplication and serve up the document it feels is the best resource/authority for the submitted query.
Types of Dupes and what to do;
There are a variety of ways the average website can run into duplicate content filtering problems without even knowing it.
Here are some common ones;
Websites with Identical Pages – Sometimes a company/individual will try to actually compete with themselves by creating other versions of their sites on a different domain name. Not a good idea. Affiliate sites with the same look and feel which contain identical content, are certainly not a good idea either. Regardless if it’s one site o many, create unique content throughout.
Scraped Content – this is content directly taken ‘verbatim’ from another site. This is obviously not a good idea.E-Commerce Product Descriptions – another common problem is ecommerce sites that use the same product descriptions from their manufacturers site. Once again – unique content. Write your own product descriptions. Also - if you have product pages with nothing substantially different from other pages: …then add fresh content.
Distribution of Articles – Do not publish articles you are using for distribution on your site. Some people will say to let the SEs index it first and then distribute it – this will not work. If you have 2 articles, put one on your site and the other into circulation.Mirror sites: 1 website, 2 domains – If you are trying to utilize 2 domains, simply forward the secondary domain to the primary at the registrar level. Do not build 2 sites that are indentical
Home Page URLs.- Having multiple home page naming conventions and Back Links to those multiple root domains. The best way to tackle these is via 301 redirects.
Here are some examples of what I mean;
http://www.brandmantra.nethttps://www.brandmantra.nethttp://www.brandmantra.net/index.php(asp/php)https://www.brandmantra.net/index.phphttp://brandmantra.nethttps://brandmantra.nethttp://brandmantra.net/index.phphttps://brandmantra.net/index.phphttp://www.brandmantra.net/home/https://brandmantra.net/home/Canonicalization issues,- confusing the bot: these are caused by dynamic URL’s. Often the bots may be returning a different URL with the same content…These are the long URLs with parameter strings the you see with many dynamic applications. These are not good as well – use the 301 methodology to ensure page naming conventions are tight.
Print-friendly pages; -. believe it or not, our little bot friends can follow the links to the printer friendly page and consider it duplicate content. For this be sure to use the robots.txt to forbid them from said pages.Boiler plates; - Pages with too many common elements that are very similar, including title, meta descriptions, headings, navigation and globally occurring text/copy. Boilerplate content is considerable amounts of text repeated on a substantial number of pages on a site.… and I shall let Google’s Adam Lasnik finish up
"Our algorithms take a look at their pages and (computerwise) ask, "What value is this site providing that users can't get from other sites or even the 'mothership'? (originator of content)"
"The fact that duplicate content isn't very cut and dry for us either (e.g., it's not "if more than [x]% of words on page A match page B...") makes this a complicated prospect."
