{"about":{"summary":"A directory of side businesses that real people say they run, each summarized in our words and linked to its public source.","notes":["Sources are public, first-person accounts: interviews, podcasts and community threads.","Cost, time and the other tags are machine estimates, each with a confidence score.","Income figures are the owner's own claim. We don't verify them."],"how_to_cite":"Link the idea page and its source. Call income figures the owner's unverified claim, and cost and time estimates."},"idea":{"slug":"math-textbooks-in-print-and-pdf-7fdd8d","title":"Math textbooks in print and PDF","summary":"Writes and sells math textbooks as print and PDF, built around curating expert knowledge.","url":"https://allsidehustleideas.com/ideas/math-textbooks-in-print-and-pdf-7fdd8d","markdown_url":"https://allsidehustleideas.com/ideas/math-textbooks-in-print-and-pdf-7fdd8d.md","tags":{"category":{"value":"physical-products","label":"Physical products","confidence":0.68},"earns_from":{"value":"one-time","label":"One-time sales","confidence":0.97},"startup_cost_estimate":{"value":"100-1k","label":"$100 to $1k","confidence":0.39},"time_estimate":{"value":"hands-off","label":"Hands-off","confidence":0.66},"where":{"value":"online","label":"Online","confidence":0.83},"needs_coding":{"value":false,"confidence":0.93}},"owner_reported":null,"source":{"publication":"Hacker News","title":"What was your best passive income in 2014?","url":"https://news.ycombinator.com/item?id=8109184","person":"ivan_ah","host":null,"date":"2014-07-30"},"owner_site":null}}