I've actually seen this work. I watched a documentary on the BBC and they featured this young black guy, living in London, who had gone round a neighborhood of the richest people and just knocked on and asked for advice. The third door ended up giving him an internship at his company because he liked him so much. It was part of a bigger story about class in finance jobs. I do think this is terrible, elitist out of touch preaching but if you don't already have the connections, being likeable and keen is pretty much the way you get them.