Economy

"An 'economy' is a practice of exchange that sustains itself, or is sustained, through time", and a practice of exchanges means "A gives something to B" or "B (directly or indirectly) gives something back to A" (Lessig, 2008, p. 117). People participate for as long as they get enough back for what they give. There are at least two types of economies - the sharing and the commercial economy. Money in the sharing economy is weird, and helping out in the commercial economy is also strange (p. 119).

References:

Lessig, L. (2008). Remix. New York; Penguin Press.