Backlinks. If content is king, then backlinks are queen. Remember, it's not about which site has the most links, but who has the most quality links pointing back to their website. Build backlinks by submitting monthly or bi-monthly press releases on any exciting company, and contacting popular blogs in your niche to see how you can work together to get a backlink from their website. Create the best possible product site you can, so people talking about the products you sell will link back. Try creating graphics or newsworthy content that will influence bloggers and news websites to link that content.
Attempting to replace a dead link with your own is easily and routinely identified as spam by the Wikipedia community, which expects dead links to be replaced to equivalent links at archive.org. Persistent attempts will quickly get your account blocked, and your webiste can be blacklisted (the Wikipedia blacklist is public, and there is evidence that Google uses it to determine rankings), which will have negative SEO consequences.
WOW. I consider myself a total newbie to SEO, but I’ve been working on my Squarespace site for my small business for about 3 years and have read dozens of articles on how to improve SEO. So far, this has been the MOST USEFUL and information-packed resource I’ve found so far. I’m honestly shocked that this is free to access. I haven’t even completely consumed this content yet (I’ve bookmarked it to come back to!) but I’ve already made some significant changes to my SEO strategy, including adding a couple of infographics to blog posts, changing my internal and external linking habits, editing meta descriptions, and a bunch more. Thanks for all the time and passion you’ve out into this.