Zappos has employed a co-branding marketing strategy. They’ve set up many sub-domains and skinned them with a different header and navigation. Some examples:
http://www.zappos.com
http://canada.zappos.com
Category-based
http://running.zappos.com
http://outdoors.zappos.com
http://rideshop.zappos.com
http://couture.zappos.com
Brand-based
http://clarks.zappos.com
http://privo.zappos.com
http://stuartweitzman.zappos.com
http://indigo.zappos.com
http://tarynrose.zappos.com
http://bostonian.zappos.com
You can get a good look at many of them with this google site search.
And while the navigation is changed and trimmed down on some of these subdomains, you can change out the subdomain in many cases and get some strange results.
Looking for a 4″ heel running shoe?
Where am I going with all this? It’s wreaking a bit of havok in google’s search results. It’s not difficult to find a search where zappos dominates 3 or 4 of the top ten natural searches with these subdomains, with many more on pages 2+.
Check out this search for “clarks trinidad“. From where I sit, they dominate 4 of the top 8 spots plus a product search result at the top.
Is this a good user experience, Google?
Hmm. The product match at zappos isn’t what you’re looking for?
How about this first result at www.zappos.com.
No? how about this same thing at canada.zappos.com
No? maybe this other page from canada.zappos.com
Ahhh, you’re not from Canada? Try this at indigo.zappos.com

Is this a happy accident?
While this may not be their primary purpose for this, I’m sure they’re enjoying the traffic. It’s all a bit spammy in my opinion and it could backfire. Well, it should backfire. Big companies have a way of getting away with this.
