This one probably doesn’t apply to your standard SMB website, but if you run a big local search site, this one’s for you.
“Faceted search” is the rubrick for a site that allows users to refine search results by categories (aka “facets”). This kind of interface appears on a lot of sites (Kayak and Kudzu are two examples that come to mind). If not implemented with care, faceted metadata search interfaces can be a huge problem SEO-wise, as they create an almost infinite set of pages for a search engine robot to get hung up on.
Consider the following sets of category metadata on a restaurant search:
By clicking around on these categories you can get a huge number of results (6*5 factorial? – any Einsteins out there?) such as:
- Chinese restaurant
- Quiet Chinese restaurant
- Romantic Chinese restaurant
- Romantic quiet Chinese restaurant
- Romantic quiet Chinese restaurant in Soho
- Romantic quiet Chinese Italian restaurant in Soho
So you get a bunch of problems – too many pages, confusing navigation and probably a duplicate page problem to boot as a lot of these pages tend to have the same data on them.
So how do you solve this and still offer faceted search?
1. Figure out which are your most important pages among the million possible combinations
2. Create linear paths for the search engine robots to follow using noindex tags, nofollow tags and your robots.txt file
3. Make sure that no page that you are pointing the bots to has more than one of each data type (e.g. quiet but not romantic, and vice-versa) – unless you think having two of a type is good for SEO, but that would involve some complex planning and coding.
4. Remember that if you already have this problem you will need to purge the problem pages from the search engines’ indexes before you try to fix it using bot herding or else the bots will never revisit your problem pages.
For more on faceted search check out the following: