Google Subdomains vs. Subdirectories

Theresub domains things to consider here.

[B]First off, Google sees sub domains as completely different sites[/B] and you can rank both in top 10 (provided everything else is in order of course).

Another gem is that if you create a new sub domain and link to it from the primary TLD it will pass a significant amount of PR or trust and authority almost immediately.

This give you a jump start in the SERPs.

Taking this a step further I would get a new A-address from your provider and host it in your target country.

Saturating the UK and the US is one of the most difficult combination in any market so I recommend all the above, plus use geo-targeting In WMC and at the least use country based meta tags.

[B]Next, as far as duplicate content goes[/B] using subdomains rather than TLD's will resolve this issue.

Just like I mentioned above Google sees these as separate domains - when it comes to SERPs; but as far as content they know that it is a sub domain and will understand based on the metas, hosting and geo-targeting that there is no duplication penalty.

Duplication penalties are caused by separate websites being identical with none of the above steps being taken, and are usually deserved.

Since you own the co.UK domain, rather than waste it away with a non-beneficial 301 (since you mentioned the lack of back links), pop a word press or php BB/vBulletin with RSS feeds on it.

You could even use a combination of automated programs like scrapebox, sick, market samurai, x-rumer (since its a brand new unpopulated forum) to auto-create profiles and populate it with posts. Set up 4-5 primary forums with random rss feeds 9in other words mix them up so they are not the exact same feed someone else is pushing).

Over time this self populated, cruise-control forum/blog will gain rankings, an you could even build a few links to it from your other sites.

I should also mention that [B]now that Google UK WMC allows geo-targeting of subdomain[/B]s you could also use this to your advantage. Create a /UK sub directory (right under the root) and put up a 300 word article referencing the UK, UK terms, and even link out to significant UK sites. Use UK meta tags and add a link in the content to the sub domain.

Do some social bookmarking on the new sub domain and ping it through 1-3rd tier ping tools like [URL=http://goo.gl/pH4h]scrapebox[/URL] . This tool also has an RSS submitter you could use for your RSS feed .co.uk forum/blog I mentioned earlier.

If you buy links, buy co.uk links to the sub domain and .com links to the US domain.

You can also use nofollow's to siphon your index PR directly down through to your sub domain. I did a post of why and how to use [URL=http://www.garythescubaguy.com/53/]nofollows here[/URL]