Barter-based economies are one of the earliest, predating monetary systems and even recorded history. People can successfully use barter in many almost any field. Informally, people often participate in barter and other reciprocal systems without really ever thinking about it as such -- for example, providing web design or tech support for a farmer or baker and receiving vegetables or baked goods in return. Strictly Internet-based exchanges are common as well, for example exchanging content creation for research.
In 2010, Shannon Lee Simmons had it easy. Though the economy was two years into its recessionary lurch, she had a secure job at Phillips, Hager and North, a boutique Bay Street investment firm. She was 25 years old and earning $55,000 a year, plus bonuses. She had no debt, no kids, and enough disposable income to jet off to Europe with her boyfriend and pay her credit card bills on time. Simmons is driven and effervescent, and has the charming tendency to slip into club-kid slang. Speaking of her time back then, she says: “I was ballin’.”
Since the 1830s, direct barter in western market economies has been aided by exchanges which frequently utilize alternative currencies based on the labor theory of value, and designed to prevent profit taking by intermediators. Examples include the Owenite socialists, the Cincinnati Time store, and more recently Ithaca HOURS (Time banking) and the LETS system.