This emphasis on competition is related to the advent of game theory in the mid 20th century around the same time. The problem is that game theory is one mental model of many to help make decisions, not the only one (Ben Thompson from Stratechery has a good post on the Prisoner’s Dilemma that is a fundamental one). Even researchers are starting to point to the fact that there are no perfect solutions (such as a Nash equilibrium) to most situations.

You’ve probably been hearing more and more about retargeting in the couple of years or so, and for good reason too. Retargeting campaigns use cookies to keep track of the internet users who visit your site so that you can continue to market to them once they leave. Have you ever shopped for an item and then suddenly noticed it following you around on other sites? That’s retargeting. And believe it or not, it really works.
The errors in technical SEO are often not obvious, and therefore one of the most popular. Mistakes in robots.txt and 404 pages, pagination and canonical URLs, hreflang tags and 301 redirects, http vs https and www vs non www versions: each of them can seriously spoil all efforts to promote the site. One quality SEO website analysis is enough to solve all the main problems in this part forever.