I am building a brochure-ware website for a company that sells products all across the world. They need the site to ask the user what region they are in before using the site; there are 5 regions. This is because there are different products offered to different regions and each region may or may not want to customize their own content. However, at launch and likely forever, most of the pages will be the exact same minus what is listed in the footer and in the product selection menu.

My question is how should I structure the sitemap for this site for best SEO? Should I be concerned with duplicate content penalties and/or cannibalizing the site's presence on the SERP?

Some considerations:

• The client wants to be able to print links directly to regional specific content bypassing any prompt for the user to select a region (to ensure they land on the target page).
• The client cannot have a 'default' region so the user must have a region specified
• "Clean" urls are important, but there is wiggle room
• The client does not want each region to have its own domain
• There will be a link on the page to allow users to specify a different region
• The client is not concerned with localization ...at this time
• Some products are available in multiple regions

A quick list of options I am considering:

1. www.site.com/region/page
2. region.site.com/page
3. www.site.com/page?region (no cookie, pages require the parameter. If visited without; the user must select a region)
4. www.site.com/page (using cookie and a splash screen if needed; could pass parameter in to set the region for direct linking)

Thanks in advance for your advice.