The first relates to internal link structure. I’ve made the mistake you say you’ve seen so often. I have a primary keyword and have used that keyword in the main navigation, linked to a page optimized for that keyword. But I’ve also got a bunch of contextual links in posts pointing to that page, usually with the keyword in the anchor text. I now understand that those internal links aren’t helping much, at least from an SEO perspective. Am I better to remove that keyword and direct link from the menu and simply link the page from multiple posts and pages within the site. Or will I get better results leaving it in the main menu and changing the contextual links in the posts to point to a related page with a different keyword?
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.
SEO is not an appropriate strategy for every website, and other Internet marketing strategies can be more effective, such as paid advertising through pay per click (PPC) campaigns, depending on the site operator's goals. Search engine marketing (SEM) is the practice of designing, running and optimizing search engine ad campaigns. Its difference from SEO is most simply depicted as the difference between paid and unpaid priority ranking in search results. Its purpose regards prominence more so than relevance; website developers should regard SEM with the utmost importance with consideration to visibility as most navigate to the primary listings of their search. A successful Internet marketing campaign may also depend upon building high quality web pages to engage and persuade, setting up analytics programs to enable site owners to measure results, and improving a site's conversion rate. In November 2015, Google released a full 160 page version of its Search Quality Rating Guidelines to the public, which revealed a shift in their focus towards "usefulness" and mobile search. In recent years the mobile market has exploded, overtaking the use of desktops, as shown in by StatCounter in October 2016 where they analyzed 2.5 million websites and found that 51.3% of the pages were loaded by a mobile device . Google has been one of the companies that are utilizing the popularity of mobile usage by encouraging websites to use their Google Search Console, the Mobile-Friendly Test, which allows companies to measure up their website to the search engine results and how user-friendly it is.
I completely agree that defintion of a target audience isa great first step, but would ask if adding in competitors to the analysis (mentioned here as a later step) helps draw out who your target audience would be via comparisons, i.e. showing who you are an who you are not - would be very interested to hear opinions on how this tactic can be used within the overall step in coordination with targeted keyword discovery.