Marcel Mauss' classic The Gift is a time capsule left to us from another era, and yet it is still widely quoted today. I think there are two types of people who cite its authority.
The cynics take Mauss to be saying that there are no disinterested gifts: that all presents and sacrifices are intended to show off the giver's power and put the recipient in the giver's debt. You can find traces of this argument in the book, certainly. But Mauss would say that this is missing the point, and missing it in a way that's peculiar to modern society.
His larger argument is that gift-giving is not at base a personal but a social act. In what he calls "archaic societies," that is self-evident. People in those societies are engaged in a constant circulation of gifts. Sometimes it is cooperative and friendly. Sometimes it is competitive and even aggressive. Often, it is both. But the expectation that gifts will be given, accepted, and reciprocated binds people together. Mauss insinuates that we still act like that in our supposedly individualistic societies much more than we let on...and to the extent that we have abandoned the ways of earlier social systems, he thinks we ought to see about bringing them back.
Socialists have liked Mauss' book for its insistence that the self-interested, calculating actor in the dramas written by economists is a recent invention. That implies to some (including Mauss) that we could easily reinvent ourselves. To me, that is far too optimistic. Social change does not happen just because people like old ways better. The ways we live, we are forced to live by the institutions we have to live under. But at least it gives the lie to the ideology that people just have to be motivated by economic self-interest now and forever. "Cast thy bread upon the waters and it shall return to thee in many days" is not a business plan. It is a hopeful moral statement about how we should live.