Also read: 7 easy passive income ideas to make money while you sleep
There’s a whole subculture of people trying to work out how to make money from the web.
In this regard, marketers are actually a little more like door-to-door salespersons, except that instead of going door-to-door, you instead have a window to the entire population (the internet, in case that wasn’t clear).
Therefore, the value comes from the informational deficit and the value proposition lies in the way in which your information can improve the life of the reader.
That said, there is benefit in choosing something more niche such as the Java example, as this reduces the competition and presents some more obvious marketing opportunities, such as programming forums.
Usually, that will be someone relatively young and fairly tech-savvy.