Ever see those really nice site navigation set ups where when you look at it, you feel like you are walking into a perfectly laid out grocery store? You should. Then again, have you ever wandered into a store and not been able to find anything you are looking for, because the layout makes no sense to anyone but the employees? Perhaps like a lot of dollar store types of retail shops. That can be frustrating, unless you have a lot of time to spend wandering the isles. Newsflash: organic search engines feel the same way. Let’s look at the application of deep site versus flat structured sites. When a site is organized using a traditional flat structure, organization runs one layer deep. That works for a blog, but not for an e-commerce site or a broad spectrum content site that covers many topics. A flat structured site may look like this: The use of flat structured navigation was once popular for search engine optimization, as the concept of having each page as close to the root as possible was a strong argument. Example: http://www.mytestsite.com/onions.html or http://www.mytestsite.com/bananas.html While a deep structured site, content and pages are grouped by joining theme, like putting all the toys in one section of the store. Example: http://www.mytestsite.com/produce/onions.html or http://www.mytestsite.com/produce/bananas.html A silo structure, then, is a form of deep structure that addresses the need to put like content with like content. For e-commerce stores, this can make much more sense than simple categorization. A siloed navigation takes into account the audience and their tendencies. Instead of building themes around just products, build them around how a person might shop. So if you know that the majority of your shoppers are parents with small children, lead them through cereal, juice and diapers on their way to the milk! Create a silo that matches the sorts of products or content pages they would be interested in. I can hear the naysayers already – bringing up the SEO value of that approach – since it may put the final page several layers deep in the file structure. Let’s look at one major advantage of a silo structure over a flat structure as it relates to PageRank. PageRank is part of the Hummingbird algorithm (for Google Search) that has a specific way of giving pages credit for all other pages that link or refer to them. That includes pages in the same site. We know that a page will share a bit of its PageRank with links on its own page. So for example, if your home page has a PageRank of 5 and it links ONLY to 5 pages, each one of the linked page will receive a flow through of 1 PageRank. Imagine, then, if you have a standard category navigation with 5,000 links. Each page would receive a PageRank flow through of .001. A silo navigation ensures the right pages get the most PageRank flow. This can help your internal pages rank better for given terms organically. It would also then make sense that the PageRank from an internal page would only lead to other internal pages that was thematically the same, strengthening the SEO content and the linking together.