Well there's certainly much romanticizing and exaggeration going on there. After all he's ultimately promoting his own website. I'd say it's not all that rare at all that one person builds a website and successfully turns a handsome profit. Or, even if not for a handsome profit, at least make it functional and learn a lot in the process. It's mostly just software engineering, on a popular framework, with tons of examples and libraries to rely on after all, and in many cases the service itself could actually just be dead simple. Of course to earn a lot might require some more UX, marketing and luck, but my point is, just "building" one is definitely not that comparable to marathon no matter how you look at it.
