From and SEO perspective, there are two important aspects of site navigation crawl ability and navigability.
Some of your competitors in the SEO business will look only at the first of these, but both factors are equally important.
First we need to consider Crawlability, or how accessible the sites pages are to search engine spiders.
In the ideal case all of the sites content will be accessible by human visitors and spiders within three mouse clicks from the home page.
Second we must consider navigability or how accessible the rest of the site is to visitors who enter through any of its landing pages.
No matter where a visitor lands you want to guide them back in to your site's sale funnel Improving Crawlability Spiders are not the most capable site visitors.
They don't accept cookies, they cant fill out forms, and they don't necessarily understand JavaScript.
They cant see the contents of images (or image maps), they don't have the flash plug-in installed and they are easily confused by simple drop-down menus and other common elements of site design.
If we want spiders to crawl a website, we have to make it easy for them In addition to making all content accessible, we must ensure that the same content is never accessible through more than one URL.
When a spider believes that it's being given duplicate content it may stop crawling and flag the site as uncrawlable.
In order to eliminate crawlability issue, on the perfect site, all content would be accessible within three mouse clicks of the home page.
This isn't a hard -and -fast rule, but in my experience it greatly improves sites crawlability.
All of the links would displays as plain text hyperlinks.
A site map, hyperlinked from every pages of the site would include links of every page on the site Such a structure would be ideal for spiders, but its not so great for usability! In the real world websites have to work for human visitors and there may be many elements of the user interface that don't fit into this ideal picture.
Improving Navigability Solving a sites crawlability issue will allow search engines to find all of the sites important content.
While it might sound good in theory, this situation creates new challenges for us.
Any page that's indexed by search engine might become a landing page for a searcher, For the homepage, category pages and products/service pages, this is not usually a problem because these pages are almost always fully integrated with the site navigation system and it's easy for visitors to find their way to other pages on the site.
As we discussed above information and support pages may also attract clicks and as long as these pages are part of the overall navigation scheme this won't be a huge problem.
However, these kids of pages are not always designed as entry pages.
Often they are intended to be destinations.
It might seem strange for a web hosting company to place advertisements on their tech support pages, since these pages are usually targeted to their exiting customers.
However if these pages attract visitors from search engines advertising on them is actually a very good idea from a navigability perspective.
Information pages are often implemented as pop-up windows.
This is a technique that's used to keep visitors on the "money pages", while providing answers to their more specific questions.
This functionality can become problematic when we look at it from an SEO perspectives, however if we make pup-up window crawlable, we need to ensure that visitors arriving at those pages from search engines can navigate to the rest of the site