Don't Use Too Many Internal Links
So, those of you who follow the Search Engine Journal blog may already have seen this advice, but I thought it might be useful to summarise it.
In a nutshell, as it says in the title, don't have too many internal links in one post as it may dilute their value. But why have internal links in the first place?
They send a signal to Google as to what your most important pages are, they help the bots crawling your website discover new content and they allow Google to examine and understand your website structure.
Let's look at each example. As regards site structure, internal links help Google understand how your website works. The links should be logical and relevant, naturally leading a reader from one post to another that offers more information on the same subject. If you have tons of links in every post, leading to every other post with no rhyme or reason, Google and your visitors will be confused.
Having too many links can dilute their importance. If you only have one or two links, then Google assumes they are really important and looks at them more carefully. If you have a lot of links, then Google will think that none of them are leading to important posts.
You also need to clearly direct your visitors. So, for example, after reading an informational post, if you want to send your visitor to a relevant product review, then that is the only internal link you should have on the original post. If you offer lots of different internal links, they might fall down a rabbit hole and never end up on your product page.
This isn't mentioned in the Search Engine article, but internal links also help with indexing. When you write a new post, link to it from an older post, ensuring it is relevant, of course. When Google next visits your site, it will land on posts it already knows exists, and will then follow any links to find your new content.
If you follow Jay's training, he has always recommended only having one internal link and one external link in a post.