When two people each have items the other wants, both people can determine the values of the items and provide the amount that results in an optimal allocation of resources. Therefore, if an individual has 20 pounds of rice that he values at $10, he can exchange it with another individual who needs rice and who has something that the individual wants that's valued at $10. A person can also exchange an item for something that the individual does not need because there is a ready market to dispose of that item.
Even before visiting the Marquesas, I had heard from men who had touched at the group on former voyages some revolting stories in connection with these savages; and fresh in my remembrance was the adventure of the master of the Katherine, who only a few months previous, imprudently venturing into this bay in an armed boat for the purpose of barter, was seized by the natives, carried back a little distance into their valley, and was only saved from a cruel death by the intervention of a young girl, who facilitated his escape by night along the beach to Nukuheva.
An alternate currency, denominated in labour time, would prevent profit taking by middlemen; all goods exchanged would be priced only in terms of the amount of labour that went into them as expressed in the maxim 'Cost the limit of price'. It became the basis of exchanges in London, and in America, where the idea was implemented at the New Harmony communal settlement by Josiah Warren in 1826, and in his Cincinnati 'Time store' in 1827. Warren ideas were adopted by other Owenites and currency reformers, even though the labour exchanges were relatively short lived.[17]
Identify your resources. What items do you have that you could easily part with? Use a critical eye to go through your home, and consider possessions you may have in storage or that another family member or friend is currently using. If you would prefer to offer services, honestly assess what you could provide for others that they would otherwise pay a professional to do. It could be a skill or a talent or hobby such as photography. 
Anthropologists have argued, in contrast, "that when something resembling barter does occur in stateless societies it is almost always between strangers, people who would otherwise be enemies."[6] Barter occurred between strangers, not fellow villagers, and hence cannot be used to naturalisticly explain the origin of money without the state. Since most people engaged in trade knew each other, exchange was fostered through the extension of credit.[4][7] Marcel Mauss, author of 'The Gift', argued that the first economic contracts were to not act in one's economic self-interest, and that before money, exchange was fostered through the processes of reciprocity and redistribution, not barter.[8] Everyday exchange relations in such societies are characterized by generalized reciprocity, or a non-calculative familial "communism" where each takes according to their needs, and gives as they have.[9]

In England, about 30 to 40 cooperative societies sent their surplus goods to an "exchange bazaar" for direct barter in London, which later adopted a similar labour note. The British Association for Promoting Cooperative Knowledge established an "equitable labour exchange" in 1830. This was expanded as the National Equitable Labour Exchange in 1832 on Grays Inn Road in London.[18] These efforts became the basis of the British cooperative movement of the 1840s. In 1848, the socialist and first self-designated anarchist Pierre-Joseph Proudhon postulated a system of time chits. In 1875, Karl Marx wrote of "Labor Certificates" (Arbeitszertifikaten) in his Critique of the Gotha Program of a "certificate from society that [the labourer] has furnished such and such an amount of labour", which can be used to draw "from the social stock of means of consumption as much as costs the same amount of labour."[19]

During economic downturns, when there is a keenly felt shortage of jobs and cash, people have historically adopted barter systems. The world’s most established bartering-style system is Switzerland’s wir: the German word for “we” as well as the abbreviation of Wirtschaftsring, which translates loosely to “economic circle.” In 1934, the economy in Switzerland had tanked—as it had in much of the world. Two businessmen who were facing bankruptcy, Paul Enz and Werner Zimmermann, gathered 15 of their associates in Zurich and hashed out a solution: a mutual credit system.
Nowinska says one of the biggest challenges Swapsity faces is that new barterers think they have nothing to offer. So they offer bad trades. Yet most people have hundreds of skills—from cooking to networking to scrapbooking. The trick is learning to recognize the value of your skills, your knowledge and your talent. Bartering attaches value to things that are not always recognized, or highly valued, in a cash economy—often hobbies that people can’t make a living on but love to do. One Barter Babe trades her homemade canned goods for gifts—mostly other crafted items—she can give away at Christmas. A Swapsity member has traded pounds of fiddleheads she picks at her mom’s house in the country for feng shui sessions.
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.
The Buy-day (Wheat) Ecological Life Associate summarizes a vision of life in Gezi as follows: "In our world, which is being poisoned and destroyed by consumer culture, we need sustainable and self-operating models of lifestyles, including a barter economy, ecological food production, arts and craftsmanship based on needs, renewable and effective energy use, agricultural models backed by society, permaculture, slow cities, transitional towns, eco-villages, district gardens and secondhand and recycling systems.
Modern barter and trade has evolved considerably to become an effective method of increasing sales, conserving cash, moving inventory, and making use of excess production capacity for businesses around the world. Businesses in a barter earn trade credits (instead of cash) that are deposited into their account. They then have the ability to purchase goods and services from other members utilizing their trade credits – they are not obligated to purchase from who they sold to, and vice-versa. The exchange plays an important role because they provide the record-keeping, brokering expertise and monthly statements to each member. Commercial exchanges make money by charging a commission on each transaction either all on the buy side, all on the sell side, or a combination of both. Transaction fees typically run between 8 and 15%.

Within the week, Simmons gave notice to her employer. By then, she’d been pining to leave for eight months and had diligently saved for the occasion. Her plan now was to barter her financial services with other women for one year. That would be enough time, she figured, to get the altruism out of her system, but not so much that she’d go broke. She would use $10,000 in savings to pay her cellphone bill and to parcel out $35 in emergency spending each week if and when bartering fell through on the basic necessities. That money would also help pay for most of the rent at the Dovercourt and Queen apartment she shared with her boyfriend, Matt, who was in the midst of changing careers. Everything else—food, clothing, haircuts, fitness, entertainment and transportation around the city—she would acquire through barter. Simmons figured she’d need to barter with 300 women to make it work. She gave the project a catchy name, Barter Babes, and started organizing a launch party.