How does Google Handle Sub Domain Sites with no Difference in Content

We have an Ecommerce Site and I plan to have sub-domains that are going to be country names:

My Original Site: mysite.com

I plan to create a Sub-Domain for the US Market: us.mysite.com duplicating the site giving it a US Flavour.

I don’t know how most sites handle subdomains.

For Example, If you take ASOS

They have a ASOS.COM
Also have US.ASOS.COM

They have the same content and the titles and product shots. Only varies in Pricing.

Is that not DUPLICATE CONTENT Issue… Awaiting your thoughts.

Regards,
Nuk

If you give Google enough clues that it is a localised version of the site then you should have no trouble. The duplicate content issue arises when you have multiple pages competing for the same topic, but if Google knows that us.domain.com/page is aimed at people in the US and uk.domain.com/page is aimed at people in the UK and so on, it should send people to the right ones. You can set preferences in Google Webmaster Tools, which should get rid of any potential confusion.