Many international companies with multi-lingual sites use machine translation such as Google Translate to translate their content. Google has recently warned against doing this. Google’s own John Mu commented in the Google Webmaster Central forums:
I just want to add a word of warning here — using automated translation tools to directly create content for your site could be seen as creating auto-generated content, which would be against our Webmaster Guidelines. Instead of just taking the output of a program like Google Translate, I’d strongly recommend at least having it corrected before putting it online. While Googlebot may initially fall for some Spanish keywords in your text, your users are not going to appreciate content that has been automatically translated and published without a review. I love Google Translate, but if you publish the results and get them indexed without having them reviewed, you’re not showing a lot of respect to your users…
John’s statement, “but if you publish the results and get them indexed without having them reviewed, you’re not showing a lot of respect to your users” is very true and any quality localization professional or translator would say the same. But, the importance touches international search engine optimization or more specifically Google’s Webmaster Guidelines.
How does using machine translation for multi-language websites without proofreading affect the guidelines? The issue lies in the way Google looks at the translated pages. When the pages are automatically translated the new pages contain auto-generated content and Google states in their guidelines that any auto-generated content may be removed from their index. Furthermore, if Google determines that most of the site is auto-generated it might remove the entire site!!
So bottom line, for international SEO best practices, make the effort to have a human either translate the text on your website or at least edit the copy that was created from a machine translation service such as Google Translate. Otherwise, your site may be banned and no website optimization efforts will help.