This way, when you do drive traffic, you know where that traffic is coming from. Otherwise, you're left in the dark. For example, if you do some content marketing on Quora.com or Medium.com, you could use the campaign source as simply Quora or Medium and the campaign medium as content_marketing and the term as the term you're working to rank for. Get the picture? Then, you'll see all the beautiful results directly in Google Analytics and you'll know specifically where your traffic came from.
I can honestly say from the experience of working on this project it is almost never as it seems. We began with targeting a very large segment of users (remember that time I talked about a keyword database of over 50,000 keywords?) but after a few months it turned out our largest (and most active) users were finding us from only a handful of targeted categories.
Guest blogging is a two-way street. In addition to posting content to other blogs, invite people in your niche to blog on your own site. They’re likely to share and link to their guest article, which could bring new readers to your site. Just be sure that you only post high-quality, original content without spammy links, because Google is cracking way down on low-quality guest blogging.