By definition, content marketing provides a useful (and usually free) resource for people searching on the net. So the first step is to research what topics people are searching for that are relevant to your product/service. I do this with various keyword tools (e.g. moz, ahrefs), and by looking at forum discussions about those topics (Quora is great for this). Then if we have the expertise to offer something useful, we write great content optimised for those topics and searches.
While I do agree on following a solid mid/long term strategy to generate sustainable growth, a Startup can often benefit immensely from hacking an unconventional marketing channel at an early point in its trajectory. If that doubles or triples your signups even for a short time, it can be immensely helpful to get investors to take you more seriously while you're grinding out the longterm strategy. It also helps to get feedback from real users while you're still in the development phase.
What would happen if the desert became a socialist country? Nothing for a while, and then there would be a sand shortage.