Organic traffic is a special kind of referral traffic, defined as visitors that arrive from search engines. This is what most marketers strive to increase. The higher you rank for certain keywords, the more often your search result appears (increasing your impressions), ultimately resulting in more visitors (aka clicks). It’s also important to note that paid search ads are not counted in this category.
Direct traffic is people who type your URL into their navigation bar, or who use a bookmark. These are your regular visitors, people who’ve discovered you in some other way and are now coming back, and — less now than in the past — people who type in a URL they’ve seen on your offline ads or who guess your web address based on your company name. Direct traffic is often the highest converting kind, but it can also be regular blog readers or your own staff. Filter your workers out if at all possible to keep your data clean. If you can’t filter them, at least ask them to use direct methods (rather than search, for example) and you may be able to identify it when you work in Analytics. Any traffic that Google can’t identify will also show up in Direct traffic, and that can include ads if you haven’t hooked up your ad accounts with your analytics, email or SMS campaigns if you haven’t tagged them for Google, and other sources that aren’t identified. Tag well and you’ll see less of this.

Another tip you can use is just reach out to the prior agency and say something like the following: “We realise you were using link networks for our website which has resulted in a Google penalty and loss in business. Can you please remove my website from any link network you have built?”. If the prior agency is decent, they will remove the links from the network.

Having large groups of content that all revolve around the same topic will build more relevance around keywords that you're trying to rank for within these topics, and it makes it much easier for Google to associate your content with specific topics. Not only that, but it makes it much easier to interlink between your content, pushing more internal links through your website.
The amount of dark social that comprises one's direct traffic is going to vary. For example, you might be diligent about incorporating tracking tokens into your email marketing campaigns, and asking your co-marketing partners to do the same when they promote your site content. Great. You won't have a huge chunk of traffic dumped into direct traffic that should really go into email campaigns. On the other hand, perhaps you're embroiled in a viral video firestorm, and a video on your site gets forwarded around to thousands of inboxes ... you don't exactly have control over that kind of exposure, and as a result you'll be seeing a lot of traffic without referral data in the URL that, consequently, gets bucketed under direct traffic. See what I mean? It depends.
This topic seems actually quite controversial. Google answered the question by what could be taken as a denial. But their answer was kind of open to interpretations. And on the other hand, there are studies (one of them from Moz) that showed linking out has an impact. So, how can you be so assertive? Is it something that comes out from your own experiments?
This community is full of opportunities if you're a fashion-based retailer. One of the major advantages is the fact that they add links to each of the products that they feature within their outfits - the links go directly to product pages. This is the holy grail for ecommerce SEO, and the traffic those links will bring through will convert at a very high rate.
Brankica, Very comprehensive list there. Can't think of anything else :D RT! I think the traffic sources that I hardly use is answering questions. I find that traffic conversion there is poor for me, so I don't focus too much on it. I think of all those in the list, focus on those that gives you the best kind of traffic. Forums can be a particularly useful one especially when people are there asking for help. Answering their questions and giving them a link that benefits their query is one good way of getting the right kind of traffic.

Otherwise you might end up polluting your website’s traffic. The pages filled with obsolete or low quality content aren’t useful or interesting to the visitor. Thus, they should be pruned for the sake of your website’s health. Low quality pages may affect the performance of the whole site. Even if the website itself plays by the rules, low-quality indexed content may ruin the organic traffic of the whole batch.

Use social media. Build a presence on social media networks like LinkedIn, Twitter, Facebook, Google+ etc. All of these activities help to get your name out and website address out on the internet. Read about how we doubled our social media audience in a week. Add share buttons to your site to make it easy for people to share your content. And write content worthy of sharing.

Fantastic post Tom! There's a lot of confusion on direct traffic to begin with. These are even more finer nuances that you have explained. I have a client whose top source of traffic is direct, and part of it is maybe due to the fact that they don't do any promotion, and it's mostly shared around internally within their team. But I just noticed that their URL is http and not https so this might be something for me to take back to the team. Thanks!
For a long time, digital marketers summed up the properties of direct and organic traffic pretty similarly and simply. To most, organic traffic consists of visits from search engines, while direct traffic is made up of visits from people entering your company URL into their browser. This explanation, however, is too simplified and leaves most digital marketers short-handed when it comes to completely understanding and gaining insights from web traffic, especially organic and direct sources.