Note: There are literally dozens of places you can use a keyphrase, from captions to comments, web addresses to “Alt” tags. Feel free to get tricky if you’d like. But generally, the less visible it is to readers, the less important it is to Google. So focus on those elements listed above. That’s what readers (and therefore Google) really care about.
Piggy back on the success of others. Create a presence on websites which are highly trafficked. This is beside the Facebooks, the Twitters, and the YouTubes. Figure out the relevant sites in your niche and get yourself linked in there. If you are a music producer, it’s Soundcloud. If you are a Joomla developer, it’s the JED. If you focus on WordPress, it’s the Plugins directory. Find the behemoth in your niche, and piggyback a ride on their success. It's also good to find a niche in your niche. Riding on somebody's success is a guaranteed way of increasing website traffic. Hence the reason people guest post. More on that later.
Not all web traffic is welcomed. Some companies offer advertising schemes that, in return for increased web traffic (visitors), pay for screen space on the site. There is also "fake traffic", which is bot traffic generated by a third party. This type of traffic can damage a website's reputation, its visibility on Google, and overall domain authority.