It's practically a scientific approach being taken by producers and record companies now. In the past, it was more hit-or-miss.
And I disagree with your assertion that there will always be good stuff to find if you look hard enough. The business is fundamentally different now. The only way to make money is by touring, and the only tours that make money are by the POP(ular) artists. Lots of lasers, fireworks, stage elevators, and other bullshit. Can you imagine a band like Jethro Tull starting today and being successful? Of course not.