Internal linking is super important, you have been reading this since the beginning of time.
But why and how does it matter for search engine listing?
The questions you should ask for self-assessment of your website are-
Is every part of your website easily accessible?
Is the navigation easy for the visitors as well as search engine bots?
If your site has multiple categories/subcategories how easy is it to navigate between the categories/ subcategories.
If you are not able to navigate yourself properly, there are chances that the search engine bot also might not be able to create an internal linking sitemap.
We ran some tests of two scenarios to study the effects of the internal linking following were the results.
Internal Linking Test-A
The website had multiple levels of categories and the accessibility of the categories was primarily kept through the main navigation menu.
We ran the test for a period of 3 ~ 5 months registering the organic traffic.
Internal Linking Test-B
The same website was modified and an additional link was provided to navigate between the categories, apart from the navigation menu.
We resubmitted the site map and ran the test for a period of another 3 months.
We noticed a hike in organic traffic for category and subcategory pages where an additional link was placed to navigate between the categories.
Not only this but also the referring pages saw a considerable hike in organic.
This generally implies that when you place a navigation internal link not only the page being linked sees a hike in organic visits but also the page that is linking to it sees hike in organic visits.