Armed with this information, ecommerce marketers can learn why some sources might be underperforming or focus efforts on sources that drive better quality traffic. In some cases, this might mean relying less on search engines and more on social media or brand awareness. Other times the opposite could be the best course of action. Either way, the Traffic Sources section in Google Analytics can help.
This is a great piece of work for references, lots of info on this, Answer sites have become less and less popular, but the you can really build your name on these sites such as forums, if you are consistent in answering questions frequently. Out of the points you have mentioned, I relay enjoy the "Guest Blogging" point, as this is a win win situation, not just putting out content on other websites, but also welcoming guest on my own site, giving readers a change and a different style of article, as everyone is unique in their own way. I'm actually posting an interview tomorrow with a well known name in the guest blogging. Whichever point one choices from above, consistency is the key, there is no point doing it once, but it should be done on frequently, and over time with patience you will start to see the rewards.
Beyond organic and direct traffic, you must understand the difference between all of your traffic sources and how traffic is classified. Most web analytics platforms, like Google Analytics, utilize an algorithm and flow chart based on the referring website or parameters set within the URL that determine the source of traffic. Here is a breakdown of all sources: