Siloing is an SEO technique that creates strong keyword related themes on your site, improving the relevancy of your site in the eyes of the search engines.
Think of how Wikipedia organizes the categories within a large page. It’s a structure designed to help people navigate the page and find the information they’re looking for. Search engines also appreciate when information is organized and easy to comprehend.
Here’s the deal. Google’s Webmaster Guidelines encourages the creation of sites that “have a clear conceptual page hierarchy.”
Creating a content silo is nothing more than ensuring your site has this hierarchy.
In doing so, not only do you make it easier for search engines, you make it better for your audience.
The only drawback, if it is one, is that creating the silos requires planning and forethought. In my experience, most companies can’t even get an editorial calendar together, which I think is way easier to accomplish than creating a silo!
Silos help organize and structure your websites link juice, authority, and keywords. Otherwise you would end up with a very flat website that does not feed into itself well.
This is also better for a user experience, and tell Google what pages relate to themselves in your website.