While it may be free, there is no one monitoring the barter ads, so you must be aware of potential Craigslist scams, and realize that you are always at risk when it comes to meetups and exchanges. For example, about a year ago, I arranged to trade massage gift certificates for housecleaning. Since the individual was coming to my home, I was more nervous than usual. However, she offered good previous references, and we  arranged for a time to meet when my husband would be home, in case an odd, unexpected, or even dangerous situation arose.
He would have heard of channels and sandbanks, of natural features of the land useful for sea-marks, of villages and tribes and modes of barter and precautions to take: with the instructive tales about native chiefs dyed more or less blue, whose character for greediness, ferocity, or amiability must have been expounded to him with that capacity for vivid language which seems joined naturally to the shadiness of moral character and recklessness of disposition.
In recent years, barter has enjoyed a resurgence as a means of countering economic insecurity, unemployment and worker exploitation. The nature of modern-day work, the pervasiveness of the Internet and the rise of social networking have all contributed to its spread. Other examples of alternative economic systems include gift economies, sharing economies and time banks.
Since the 1830s, barter in some western market economies has been aided by exchanges which use alternative currencies based on the labour theory of value, and which are intended to prevent profit-taking by intermediaries. Examples include the Owenite socialists, the Cincinnati Time store, and more recently[when?] Ithaca HOURS (time banking) and the LETS system.

Yet after three years with the firm, she was dissatisfied. She was spending all her time advising millionaires when she wanted to work with average Torontonians, especially women. She couldn’t help noticing that most of her female friends were broke, confused and floundering. Online, her social media feeds were filled with panicky talk of recession budgets and empty wallets. There was one problem: those women couldn’t afford to pay her, and she certainly couldn’t afford to work for free. “I really wanted to do it,” she says, “but I couldn’t figure out a business model.”
mid-15c., apparently from Old French barater "to barter, cheat, deceive, haggle" (also, "to have sexual intercourse"), 12c., of uncertain origin, perhaps from a Celtic language (cf. Irish brath "treachery"). Connection between "trading" and "cheating" exists in several languages. Related: Bartered; bartering. The noun is first recorded 1590s, from the verb.

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.