Having a different description meta tag for each page helps both users and Google, especially in searches where users may bring up multiple pages on your domain (for example, searches using the site: operator). If your site has thousands or even millions of pages, hand-crafting description meta tags probably isn't feasible. In this case, you could automatically generate description meta tags based on each page's content.

Instead, in this instance, we started at wireframe stage, plopping in keywords and meta tags. Of course, the site really needed those things, and although it launched technically “optimized”, it wasn’t enough to provide a better product than our top competitor(s). A product that people want to visit, revisit, email to friends, share on social networks, and link to more than our competitors. It wasn’t even enough to move up in the rankings.

Excellent post Brian. I think the point about writing content that appeals to influencers in spot on. Could you recommend some good, manual strategies through which I can spot influencers in boring niches *B2B* where influencers are not really talking much online? Is it a good idea to rely on newspaper articles to a feel for what a particular industry is talking about? Would love to hear your thoughts on that.

If you haven’t used software like BuzzSumo to check out what your competitors are up to, you’re at a huge disadvantage. These services aggregate the social performance of specific sites and content to provide you with an at-a-glance view of what topics are resonating with readers and, most importantly, making the rounds on social media. Find out what people are reading (and talking about), and emulate that kind of content to bring traffic to your website.
You can confer some of your site's reputation to another site when your site links to it. Sometimes users can take advantage of this by adding links to their own site in your comment sections or message boards. Or sometimes you might mention a site in a negative way and don't want to confer any of your reputation upon it. For example, imagine that you're writing a blog post on the topic of comment spamming and you want to call out a site that recently comment spammed your blog. You want to warn others of the site, so you include the link to it in your content; however, you certainly don't want to give the site some of your reputation from your link. This would be a good time to use nofollow.
For example, we regularly create content on the topic of "SEO," but it's still very difficult to rank well on Google for such a popular topic on this acronym alone. We also risk competing with our own content by creating multiple pages that are all targeting the exact same keyword -- and potentially the same search engine results page (SERP). Therefore, we also create content on conducting keyword research, optimizing images for search engines, creating an SEO strategy (which you're reading right now), and other subtopics within SEO.
Search engines use complex mathematical algorithms to interpret which websites a user seeks. In this diagram, if each bubble represents a website, programs sometimes called spiders examine which sites link to which other sites, with arrows representing these links. Websites getting more inbound links, or stronger links, are presumed to be more important and what the user is searching for. In this example, since website B is the recipient of numerous inbound links, it ranks more highly in a web search. And the links "carry through", such that website C, even though it only has one inbound link, has an inbound link from a highly popular site (B) while site E does not. Note: Percentages are rounded.