Phone farming is a technique where multiple smartphones are run together to generate passive income. Unlike crypto mining, it doesn’t require expensive hardware — just old phones, a laptop or PC, and some basic know-how. Popular in countries like China, Bangladesh, and the Philippines, where secondhand phones are easy to find, it’s also practiced by hobbyists in the US and Europe on a smaller scale. Earnings per phone are modest, often just a few cents to a couple of dollars a day, but scaling up with dozens or hundreds of devices can bring in hundreds or even thousands of dollars per month. While it can be a fun and creative side hustle, it comes with risks such as app bans and account restrictions, and profits are rarely guaranteed.