"The point that a free gift has no power to bind was recognized, according to [F.] Pollock and [F.W.] Maitland..., from the earliest period in English law. No court would uphold gratuitous gifts of enforce gratuitous promises. From this arose the custom that the giver of a gift should receive in return some valueless trifle, just enough to make an exchange and therefore a legally valid transaction. Dan takes the opposite course: by remaining a resolutely free gift it remains free of obligation.
"While the concept of a "pure gift" has often been dismissed as naive and unsociological, that of a "pure commodity" has been shown more latitude. [James] Carrier..., in a general discussion of commodity exchange, makes the point that commodities are fungible. He then notes that this is not always equally so. Works of design, art, and craft are not interchangeable one for another, and it matters by whom they were made; yet they are exchanged as commodities. However, he continues, "these qualifications do not contradict the point that commodities are impersonal. Instead they show that not everything we buy and sell is a pure commodity."....Similarly, not all that we give and receive is a pure gift. I have suggested that almost nothing ever could be.. But in so far as the Jain case is a guide, it suggests that impersonality, if it is a feature of the commodity (which seems reasonable enough), is equally a feature of the free gift, rather than being, as incautious reading of Mauss has led us to expect, a dimension along which these two kinds of transaction are opposed. No doubt this explains why religious charity and philanthropy in all the great religions have repeatedly rediscovered the supreme value of the anonymous donation only to find that time and again donors have been more attracted to the benefits of the socially entangling Maussian gift, which does make friends."
quoted from James Laidlaw's discussion of the Jain tradition of Dan or alms-giving in "A Free Gift Makes no Friends" in Mark Osteen, ed. The Question of the Gift: Essays across Disciplines. Routledge, London & New York, 2002