Things get worse with localization. There are a number of different approaches:
- Subdomain - this is how Wikipedia does it, so you have "en.wikipedia.org" and "fr.wikipedia.org"
- Area - this is what Apple does (and they probably do it because they couldn't register Apple.co.uk) - they have "apple.com/uk" and "apple.com/fr", this frees up subdomains for different conceptual websites, e.g. "store.apple.com" which in turn has "store.apple.com/uk"
- gTLD - this is what the majority of multinational corporate sites do, especially Microsoft - microsoft.com for global and USA-specific information, microsoft.co.uk for UK-specific details, and so on.
All three approaches are valid, however none of them solve the duplicate information problem, and any approach using DNS (the first and third) risks poor SEO. In practice, I give Apple the most points for good execution, but I think the gTLD option is the best in the long-term but Microsoft just tends to blow it.
I note that Dell (and HP) have adopted a kind of anti-pattern here, their websites make Microsoft.com look like a well-manicured private library. Product information is inconsistent across different geographical websites, the website itself is slow, and it's easy to think you're on your local website when it turns out you've been surfing the USA site all along. Their domain names are also rather cryptic: "www1.euro.dell.com" for example. Dell is a multi-billion-dollar company, they should be able to mask implementation details behind their domain name. Dell is bigger than Google (in terms of employees and revenue) so why do they appear so second-class?