Grant compares two websites with two different systems of exchange: Craigslist and Freecycle. Craigslist, a site where users can buy and sell items, operates on a transactional basis, whereas Freecycle is based on a system of giving and receiving items for free. Grant examines the norms of reciprocity on both sites as well as the degree to which participants on the sites identify with the sites’ communities. He finds that, of the participants who either bought or received many items, those who used Freecycle identified more strongly with the site’s community compared to those who used Craigslist. This is because, in a system of generalized giving, items are given as gifts rather than in a transactional manner, which emotionally lends the exchange greater value. Moreover, members who participate in generalized giving perceive their gifts as coming from a community rather than a transactional exchange with an individual.

Grant introduces what he calls “the altruism debate,” which focuses on the question of why humans give to others (219). On one end of the debate is C. Daniel Baston, who argues that humans are capable of pure altruism and that people give to others out of empathy and a sense of oneness. On the other end is Robert Cialdini, who thinks that humans act generously toward others when they want to relieve their own guilt or pain.