Regarding internal linking, i believe that in the case of two links pointing to an internal page, being one of those links in the group i mentioned above, they will considered only the one witch feed the algorithm with more information. In sites that have the menu before the content, it will be the second link. I think that’s the smart way for them to analyse all the links to better understand the destination page content. And they are smart 😉 .
When would this be useful? If your site has a blog with public commenting turned on, links within those comments could pass your reputation to pages that you may not be comfortable vouching for. Blog comment areas on pages are highly susceptible to comment spam. Nofollowing these user-added links ensures that you're not giving your page's hard-earned reputation to a spammy site.
Like the hundreds of people already, I thought this was an amazing post. You have a great way of breaking things down into ways that the average reader will be able to understand and make actionable. I think this is a great resource for our readers, so I included it in my monthly roundup of the best SEO, social media, and content marketing articles. https://www.northcutt.com/blog/2014/02/january-resource-round-up-the-best-of-seo-social-media-and-content-marketing/
Consistent Domains: If you type in www.example.com, but then your type in just example.com and the “www” does not redirect to www.example.com, that means the search engines are seeing two different sites. This isn’t effective for your overall SEO efforts as it will dilute your inbound links, as external sites will be linking to www.example.com and example.com.
Thanks for the great post. I am confused about the #1 idea about wikipedia ded links…it seems like you didn’t finish what you were supposed to do with the link once you found it. You indicated to put the dead link in ahrefs and you found a bunch of links for you to contact…but then what? What do you contact them about and how do you get your page as the link? I’m obviously not getting something 🙁