When barter has appeared, it wasn’t as part of a purely barter economy, and money didn’t emerge from it—rather, it emerged from money. After Rome fell, for instance, Europeans used barter as a substitute for the Roman currency people had gotten used to. “In most of the cases we know about, [barter] takes place between people who are familiar with the use of money, but for one reason or another, don’t have a lot of it around,” explains David Graeber, an anthropology professor at the London School of Economics.

This sort of scenario was so undesirable that societies must have created money to facilitate trade, argues Smith. Aristotle had similar ideas, and they’re by now a fixture in just about every introductory economics textbook. “In simple, early economies, people engaged in barter,” reads one. (“The American Indian with a pony to dispose of had to wait until he met another Indian who wanted a pony and at the same time was able and willing to give for it a blanket or other commodity that he himself desired,” read an earlier one.)
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.
In his analysis of barter between coastal and inland villages in the Trobriand Islands, Keith Hart highlighted the difference between highly ceremonial gift exchange between community leaders, and the barter that occurs between individual households. The haggling that takes place between strangers is possible because of the larger temporary political order established by the gift exchanges of leaders. From this he concludes that barter is "an atomized interaction predicated upon the presence of society" (i.e. that social order established by gift exchange), and not typical between complete strangers.[13]