Three days ago, a 2004 BBC documentary on the life of 16th century composer William Byrd was listed by Amazon with a sales rank lower than 110,000. Who even knew it existed?
Yesterday, the sales rank was 11,000 — having shot up 100,000 points.
Why and how? It was put online by someone, but not the BBC, and widely linked, to the cheers of everyone involved in the production but probably to the annoyance of the IP owners. The lesson is one that bears repeating again and again. The enemy of commercial success is not piracy; it is obscurity.