The whole point of barter is to satisfy a need. A valuable barter is whatever a barterer needs at that moment. Raj Dhiman, a 30-year-old chemist, joined Swapsity at the beginning of 2012. For his first barter, he traded a batch of home-baked gluten-free muffins in return for a full weekend first aid course. Unlike the course’s instructor, Dhiman relished the challenge of perfecting the recipe. Since then, he’s exchanged a lesson on how to create a website for an Indian cooking class. He’s also turned away barter offers that he didn’t find personal value in. “It’s perfectly fine to decline,” he says, “It wasn’t like, ‘Whoa, whoa, whoa. What is this person thinking?’ I’d say, ‘I appreciate the offer, but that’s not what I need right now.’ All you have to do is ask for what you need.”

Other anthropologists have questioned whether barter is typically between "total" strangers, a form of barter known as "silent trade". Silent trade, also called silent barter, dumb barter ("dumb" here used in its old meaning of "mute"), or depot trade, is a method by which traders who cannot speak each other's language can trade without talking. However, Benjamin Orlove has shown that while barter occurs through "silent trade" (between strangers), it also occurs in commercial markets as well. "Because barter is a difficult way of conducting trade, it will occur only where there are strong institutional constraints on the use of money or where the barter symbolically denotes a special social relationship and is used in well-defined conditions. To sum up, multipurpose money in markets is like lubrication for machines - necessary for the most efficient function, but not necessary for the existence of the market itself."[12]
Although, as a general case, a ship unlucky in falling in with whales continues to cruise after them until she has barely sufficient provisions remaining to take her home, turning round then quietly and making the best of her way to her friends, yet there are instances when even this natural obstacle to the further prosecution of the voyage is overcome by headstrong captains, who, bartering the fruits of their hard-earned toils for a new supply of provisions in some of the ports of Chili or Peru, begin the voyage afresh with unabated zeal and perseverance.

On paper, this sounds a bit like delayed barter, but it bears some significant differences. For one thing, it’s much more efficient than Smith’s idea of a barter system, since it doesn’t depend on each person simultaneously having what the other wants. It’s also not tit for tat: No one ever assigns a specific value to the meat or cake or house-building labor, meaning debts can’t be transferred.