Faceted navigation is a pain in the @&$. 

Seriously.  But then I looked to an authority site who I assumed HAD to be using faceted navigation to supply users with dozens of different kinds of combinations of different products: Amazon.com.  This behemoth site is on nearly all of my search queries, not excluding the desired search terms of my employer. I thought, they must be using faceted navigation, so how do they do it?

Amazon employs a seemingly basic User-Agent detection to serve an alternatively coded version to Googlebot that is more search friendly.  Is this black-hat?  I would say no.  Is this cloaking?  Kinda...but you have to consider the intent of it.  They aren't maliciously cloaking to serve up some devious content rich with evil keywords and ackward text-links.  They are rendering the menu differently, but keeping the same content pretty much.  Take a look at what I mean.

What you see when you navigate to Amazon:

Check out those faceted navigation links.  NASTY RIGHT!?

Now, check out what you see when you come strolling through as Googlebot:

Wow, look at that...The faceted navigation just vanished!  It's like some kind of SEO Christmas miracle.  Now, search engines have no choice but to crawl the links individually, with no possibility for arriving at the faceted navigation.

Another thing to notice.  Notice that for Googlebot, the parameters are not being pulled, and the page is no longer about Amazon or Apple electronics, but simply Electronics. 

Success!

Or not?  What if somebody decides they want to link to that sweet Amazon page about Apple AND Amazon brand electronics?  

Sneaky Parameters

Navigate to a section of Amazon's website and refine it by a couple of different brands.  Take a look at the resulting URL.

http://www.amazon.com/gp/search/ref=sr_hi_1?rh=n:172282&ie=UTF8&qid=1294154939#/ref=sr_nr_p_4_1?rh=n%3A172282%2Cp_4%3AAmazon%7CApple&bbn=172282&ie=UTF8&qid=1294155388&rnid=15784691

Notice the highlighted part of the URL.  The page is being loaded with parameters after the hash mark being passed to the server (Note: This must be done with JavaScript voodoo). Google will ignore all parameters that are passed after the hash mark.  This means that Google will not be crawling any URLs that are a result of faceted navigation. 

How does this help you?

As an in-house SEO, I am frequently tasked with diagnosing sections of the website that require me to do some research beyond my innate SEO knowledge.  In an original 10 minute SEO assessment, I kind of glossed over a couple of things Amazon.com did for SEO, but I wanted to break one strategy down further.

I wanted to break it down and analyze it, because I feel that when I really tackle something and write about it, I get a much more comprehensive understanding of what it is they're doing.  Only when I have a full understanding can I take a concept and see if it is applicable to my needs.  If it is, then this understanding will allow me to communicate the requirements coherently to all parties that will be taking action to implement my recommendation. 

Amazon.com's approach may not be right for you.  Heck, this is one of what I'm sure are dozens of ways to approach faceted navigation.  But I strongly believe that it is important for all SEO's to know what is going on in the world of enterprise level SEO.  These are the leaders of e-commerce.  There are many tactics I have picked up from picking apart what the leaders of industry are doing in the realm of SEO. 

If this goes over well, I may post a followup about different strategies I've found that get little discussion.  If it doesn't then I will retreat back to lurker status and continue the anonymous thumb upping and downing.