This is so unscalable, it's a non-starter. This guy got a job because he had already proven himself by making an app, and a combination of persistence, boldness

This is so unscalable, it's a non-starter. This guy got a job because he had already proven himself by making an app, and a combination of persistence, boldness and luck. The work for free part removed a friction-point in the hiring process, but I think it's a safe guess that it wasn't the primary factor in securing him the job. The method should be, "if you're closed to be hired somewhere, but feel there's some friction for the company to make the decision, offering a free trial might work." And of course there's the back of the medal: offering to work for free sends very strong signals of desperation and placing a low premium on your own abilities. Offering to work for free does not significantly reduce overhead. Introducing a new hire to the project, code, repository, bug-tracker and reviewing his work IS overhead. Saying "Hi, meet Nick, he flew in on his own dime to do your jobs for free" to the team is a morale-killer. Killing morale IS overhead.