Every year millions of Hindus shave their heads in offering to the gods. It's called tonsuring, and it's big business. "On average we are getting in excess of five tonnes...", says hair dealer Mayoor Balsara as he finalises his latest purchase from the temples. It's a classic globalisation story: the sacrificial hair is cheaply sourced in the developing world, and is lining the pockets of those in the west. David Gold is one of them. Each year his company turns over $150 million selling hair extensions sourced from India's temples. He deflects questions of ethics, arguing that the temples pour profits back into local welfare projects. It's a dubious claim, and yet many Hindus seem happy for their hair to be spun into gold: "We gave it to God, and it's come back like this. It's beautiful."