Ask HN: How much passive income do you generate, and from what? 8 years ago
Referral or Partner Program is one of the options of the passive income. In most cases, you get a share from a commision that a person you've referred a product/service to has paid. One of the examples is https://www.crazycall.com/partners?source=news.ycombinator. Your could also do blogging or create youtube videos.