A lot of times, a page may not rank well for specific keywords because the link structure between pages isn't really a "structure" but more of a diluted spider web of links. Siloing is a structural solution to this problem. Siloing is a way to group pages that belong to a central theme. There are two types of siloing, directory-based and virtual siloing. This entry focuses on virtual siloing.
The term "siloing" comes from an analogy involving grain silos you see in the mid-west. If you've ever traveled through that area, you'll know that there are points where you see miles of practically nothing and then out of nowhere, a grain silo appears. The analogy comes from the fact that if you use this "siloing" technique that I'm about to mention, it will make your page stand out to the search engines much like a grain silo stands out to a driver.
A virtual silo is a linking strategy. The "silo" is the thematic center point of your structure. You will need to have supporting pages that link underneath this hub. These are the pages that are thematically similar to each other but are sub-themes of the silo. You also want to link horizontally between these support pages to build up page rank among them in order to transfer more to your central page. In a sense, you're performing the third-level push mentioned in the Advanced Page Rank Manipulation Techniques Part I blog but also including a central page into the picture. The whole idea with siloing is to create a disproportionate amount of links to important pages in order to make them seem more relevant to the search engines. Siloing is a beneficial technique for boosting page rank but if not done properly, it can really mess your SEOing efforts up, so use this procedure with caution.
