Organic traffic is the primary channel that inbound marketing strives to increase. This traffic is defined as visitors coming from a search engine, such as Google or Bing. This does not include paid search ads, but that doesn’t mean that organic traffic isn’t impacted by paid search or display advertising, either positively or negatively. In general, people trust search engines, and sayings such as “just Google it” reinforce that humans are tied to the search engine. Thus, paid search, display, or even offline campaigns can drive searches, which may increase organic traffic while those campaigns are running.
Visual assets aren’t regular images you might pull from a Google Image search. Instead, these are unique diagrams or infographics you’ve created specifically for your epic content. These kinds of diagrams or infographics explain a theory, communicate a point, or showcase data in exciting and interesting ways—and gain attention (and links) because of it.
The following example shows a Client who receives 55% of their website traffic from Organic Search – typically this is a strong performance, but again this will vary greatly based on paid search. More important than the % is the number of sessions itself – this tells us how many visits (note: not unique visitors) we received through this channel. In this example, we have 7486 visits in 1 month that all came from organic searches.
Regarding RankBain, my own assumption is that user signals are part of the training data RankBrain gets (even though Paul Haahr does not confirm that in the talk at SMX or the discussion afterwards). If that is true, then RankBrain will see your high CTR and maybe TOS, might try to figure out what pattern causes them and MIGHT try to change it’s own algorithm in a way that ranks results LIKE YOURS higher.
Because so few ordinary users (38% according to Pew Research Center) realized that many of the highest placed "results" on search engine results pages (SERPs) were ads, the search engine optimization industry began to distinguish between ads and natural results.[citation needed] The perspective among general users was that all results were, in fact, "results." So the qualifier "organic" was invented to distinguish non-ad search results from ads.[citation needed]

The Google, Yahoo!, and Bing search engines insert advertising on their search results pages. The ads are designed to look similar to the search results, though different enough for readers to distinguish between ads and actual results. This is done with various differences in background, text, link colors, and/or placement on the page. However, the appearance of ads on all major search engines is so similar to genuine search results that a majority of search engine users cannot effectively distinguish between the two.[1]

Well, yes and no. Sure, you can get hit with an algorithm change or penalty that destroys all your traffic. However, if you have good people who know what they are doing, this is not likely to happen, and if it does, it is easy (in most cases) to get your visits back. Panda and Penguin are another story, but if you get hit by those it is typically not accidental.
Many blogging software packages automatically nofollow user comments, but those that don't can most likely be manually edited to do this. This advice also goes for other areas of your site that may involve user-generated content, such as guest books, forums, shout-boards, referrer listings, etc. If you're willing to vouch for links added by third parties (for example, if a commenter is trusted on your site), then there's no need to use nofollow on links; however, linking to sites that Google considers spammy can affect the reputation of your own site. The Webmaster Help Center has more tips on avoiding comment spam39, for example by using CAPTCHAs and turning on comment moderation.

At our agency, we work with sites of varying sizes, from very large to quite small, and recently, we have noticed a trend at the enterprise level. These sites aren’t relying as much on Google for traffic any more. Not only are they not relying on Google traffic, but also, the sites are getting less than 10 percent (or slightly more) of their organic traffic from the search giant. How To Get Organic Traffic From Google