Imagine a talent shortage; you are lacking skilled programmers. No, really! :-)
So what you do is print out (say, on matchbook covers) a very small ad "Learn programming! Start a career!" with a phone number to call and you basically spam the whole country / world with these things. And a few people call in, and you screen them, and a few of those you bring in and talk to, and a few of those you might wind up hiring. And you plonk them into a classroom and teach them some programming, and a few people turn out to be just incredibly good natural programmers that you might not have gotten otherwise. (The ones you hired that didn't work out so well? You use them on government contracts).
IBM's model in the 1970s (and probably a few other shops as well).
It takes quite an investment, and you need to be able to deal with people at scale, which is something that start-ups and even most big companies (like Microsoft) are terrible at, for various reasons.