Know-how trading is a web-based research and design phenomenon related to open innovation and crowdsourcing.
Know-how trading sites differ from open innovation communities in that the entry level for solutions is much lower.
Some individuals use know-how trading portals in an informal way to accumulate new knowledge about subjects which they are interested in.
Generally, any individual can sign up for a know-how trading portal for free and browse the selection of questions and challenges by reward and subject.
Innovation communities such as Experts-Exchange and Mahalo Answers work on a similar business model but paying rewards in an artificial currency.