When you look at most websites that have been published in the past five years, one thing you’d notice is that most sites have the main navigation going horizontally across the top of the site. Before then, some sites had the main navigation going vertically down the left hand side of the page. Vertical navigations really don’t fit in many current designs, and for very good reasonThere are typically three main sections on a website- the header, the content, and the footer. The header section contains the main navigation, logo, and possibly a slideshow or tagline. The content section is generally split in to two sections (the main content and the sidebar). And the footer section is located at the bottom of the site and contains the copyright notice and possibly some additional contact information or links. The problem with moving to a vertical navigation is that it generally takes the place of the sidebar. The sidebar is a great place to add in additional links to other pages or other content that the user might be interested in reading, which can have a great impact on your search engine ranking in leading search engines. So by moving the navigation to the side, you cut in to some very important space for the sidebar. As one of my instructors in college said, it cuts into the room for dancing. You can do a design with 3 columns, but those tend to get a little cluttered and messy and more difficult for users to navigate through.
My biggest issue with vertical navigations is simply that most people aren’t as familiar or comfortable with them. I’m not a huge fan of drop down menus from the navigation, but I will do them for a more complex site. When a vertical navigation is used, the only really option would be a flyout menu, which is very confusing to many people (myself included at times). I may not be a big fan of drop down menus, but I will use them if the situation is right. A flyout menu I simply will not design.
Because of the valuable space they take up and the added confusion for many users, I am not a fan of vertical navigations. Truth be told, I’m not really sure what a benefit of them would be.