Multiple Domain Names Penalty

If you own a web site AND you have multiple domain names registered, you might want to read this with your full attention. There are a great many web sites out there which, by inappropriate use of multiple domain names, effectively cripple their search engine rankings by blatantly breaching search engine guidelines!Site owners often register more than one domain, and there are sound reasons for doing this, including;

• The main URL includes a keyword phrase but is too long to type quickly, so a shorter, cryptic one is utilised and maybe is also used on business cards and letter heads.
• You take various versions of domains to prevent competitors from grabbing them - dot.com, dot.co.nz, dot.biz, dot.info etc, and point them all to the "main" site.
• You take various country versions - dot.co.nz, dot.com.au, dot.co.uk because you are going to expand into those markets - but in the interim you point them all to the "main" site.
There are also misguided reasons for doing this, including; Having multiple domains pointing to the same location in the hope that the search engines will be duped into indexing ALL of them as different content, giving you lots of top rankings under different domains. Search engines hate duplicated content with a passion but their automated spiders and bots cannot determine which category YOU fall into - uninformed and innocent of intent, or deliberately and knowingly manipulative. So all sites who transgress can expect to be treated equally. And yes, you can be banned from the SE indexes for getting it wrong! The search engines do not give out many guidelines - in fact they are all very coy about giving too information much away. However, when they do make a statement by way of guidelines, regardless of how politely it is worded, you had best sit up and take notice because they are really, really serious about it! Google Guidelines on Multiple Domains In the case of Google, their Webmaster Guidelines are unambiguous! E.g. on this page;