I am designing a website, which links off to many microsites (e.g., product, promotional, etc.) that the client would like to keep intact. Many of these microsites can be assessed through contextual navigation on an appropriate page, but some warrant global access. Would it be appropriate to link these within extra site navigation? The only problem is that extra site navigation seems to work best when it links to other properties/companies (ex: sears.com, att.com, google.com) as opposed to product/promotional microsites.