The "Direct Session" dimension, not to be confused with the default channel grouping or source dimension, is something different. It can tell you if a session was genuinely from its reported campaign (reported as No), or if it was simply bucketed there due to the last non-direct click attribution model (reported as Yes). I didn't mention this dimension in the article because it has some flaws which can cause brain bending complexities, plus it goes a little beyond the scope of this article, which I tried to gear more towards marketers and non-expert GA users. It's certainly an interesting one, though.
Selecting “All Traffic Sources” from Google Analytics left-side navigation will show you a table listing the most active traffic sources and their medium. Direct traffic, as you would expect, has a medium of “none.” Traffic from Facebook, as an example, will have a medium of “referral.” Search engine traffic will have a medium or “organic” or “CPC” as described above.
Optimise for your personas, not search engines. First and foremost, write your buyer personas so you know to whom you’re addressing your content. By creating quality educational content that resonates with you>r ideal buyers, you’ll naturally improve your SEO. This means tapping into the main issues of your personas and the keywords they use in search queries. Optimising for search engines alone is useless; all you’ll have is keyword-riddled nonsense.
Referral traffic in Google Analytics can also include your social traffic or even your email visits. This is largely because there are different ways to track data and there are imperfections in the system, but it also depends on which reports you look at. For example, Acquisition> All channels> Referrals will include much of your social traffic, but the default All channels report does not include Social in your Referrals. The best solutions:

AllRecipes: This site is one of the larger recipe-focused sites on the web, and it also has a reputation amongst foodies for having a ton of comments about “this recipe was terrible, also I made X, Y, and Z substitutions.” You, too, can take advantage of these recipe comments to promote your own changed version of the recipe, if you have a cooking blog.
Secure (https) to non-secure sites (http): Since Google began emphasizing the importance of having a secure site, more websites are securely hosted, as indicated by the “https” in their URLs. Per the security protocol, however, any traffic going from a secure site to a non-secure site will not pass referral information. For this issue, you can correct by updating your site to be secure through a third-party SSL certificate.