The SMX Confernece was in Sydney Australia last week, and one topic discussed by representatives of both Google and Yahoo was that of duplicate content filtering across international domains. Rand Fishkin of SEOmoz notes that while the subject has been discussed in the past, many people including experts in the field have been in the dark.

He highlights what Yahoo and Google (respectively) search engineers Priyank Garg and Greg Grothaus had to say about the matter:

Priyank, when asked about best practices for "localizing" English language content across domains, noted that Yahoo! does not filter duplicate content out of their results when the works are found on multiple ccTLD domains. Greg confirmed that this is also how Google's engine behaves and, with the exception of potentially spammy or manipulative sites, reproducing the same content on, for example, yoursite.com, yoursite.co.uk and yoursite.com.au was perfectly acceptable and shouldn't trigger removal for duplicate content (assuming those sites are properly targeting their individual geographic regions).

Fishkin also notes that for usability and conversion reasons, it's best to localize languages anyway, just to create a better user experience. Vanessa Fox (formerly of Google) has a very in-depth article on "Making Geotargeted Content Findable For the Right Searchers," which also discusses the issue. She recommends the following:

- Putting content for each country on a subdomain or subfolder. (Either is fine; but  if you’re starting from scratch and have a choice, I’d generally suggest going with a subdomain.)

-  Ensuring all content (including title tag and meta description) is localized.

-  Focusing on regional link-building efforts. For instance, make sure that your PR team is targeting newspapers in local regions, not just near the corporate office.

- Including location-specific terms in internal anchor text. For instance, you might want to create an HTML site map that links to each country’s “home page” on the domain.

Fox's article contains a ton of additional useful information on international SEO, an important topic for any business looking to expand their customer-base around the globe.

Country-specific TLDs can contribute to relevancy factors that potentially make your site rank higher according to Fox. While there are exceptions, the subject is something definitely worth giving some thought to.