One morning last year, Jacobus Louw set out on his daily neighborhood walk to feed the seagulls he finds along the way. Except this time, he recorded several videos of his feet and the view as he walked on the pavement. The video earned him $14, about 10 times the country’s minimum wage, or for Louw, a 27-year-old based in Cape Town, South Africa, half a week’s worth of groceries.

The video was for an “Urban Navigation” task Louw found on Kled AI, an app that pays contributors for uploading their data, such as videos and photos, to train artificial intelligence models. In a couple of weeks, Louw made $50 by uploading pictures and videos of his everyday life.

Thousands of miles away in Ranchi, India, Sahil Tigga, a 22-year-old student, regularly earns money by letting Silencio, which crowdsources audio data for AI training, access his phone’s microphone to capture ambient city noise, such as inside a restaurant or traffic at a busy junction. He also uploads recordings of his voice. Sahil travels to capture unique settings, like hotel lobbies not yet documented on Silencio’s map. He earns over $100 a month doing this, enough to cover all his food expenses.

And in Chicago, Ramelio Hill, an 18-year-old welding apprentice, made a couple hundred dollars by selling his private phone chats with friends and family to Neon Mobile, a conversational AI training platform that pays $0.50 per minute. For Hill, the calculation was simple: he figured tech companies already capture so much of his private data, so he might as well get a cut of the profit.

These gig AI trainers – who upload everything from scenes around them to photos, videos and audio of themselves – are at the frontlines of a new global data gold rush. As Silicon Valley’s hunger for high-quality, human-grade data outpaces what can be scraped from the open internet, a thriving industry of data marketplaces has emerged to bridge the gap. From Cape Town to Chicago, thousands of people are now micro-licensing their biometric identities and intimate data to train the next generation of AI.

This ends well.