But various anthropologists have pointed out that this barter economy has never been witnessed as researchers have traveled to undeveloped parts of the globe. “No example of a barter economy, pure and simple, has ever been described, let alone the emergence from it of money,” wrote the Cambridge anthropology professor Caroline Humphrey in a 1985 paper. “All available ethnography suggests that there never has been such a thing.”
The first 23 Barter Babes to join were friends and former PH&N co-workers who wanted to support Simmons. They mostly traded items and services to help out with the launch party: a lot of food, a press release, coat racks, silent auction items, courier services and social media consulting. Barter Babe No. 24, Grace Poon, was the first person to sign up for the project with whom Simmons had no prior connection. In exchange for Simmons’s financial advice, Poon provided graphic designs for an investment presentation (which Simmons still uses today). She remembers being excited, but also nervous: it was the first trade she’d made with someone who didn’t feel obligated to give her unconditional support. She needn’t have worried.
The man who arguably founded modern economic theory, the 18th-century Scottish philosopher Adam Smith, popularized the idea that barter was a precursor to money. In The Wealth of Nations, he describes an imaginary scenario in which a baker living before the invention of money wanted a butcher’s meat but had nothing the butcher wanted.“No exchange can, in this case, be made between them,” Smith wrote.
While one-to-one bartering is practiced between individuals and businesses on an informal basis, organized barter exchanges have developed to conduct third party bartering which helps overcome some of the limitations of barter. A barter exchange operates as a broker and bank in which each participating member has an account that is debited when purchases are made, and credited when sales are made.

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. 

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.