Closing the deal: Salesman (dir. Albert Maysles, David Maysles, & Charlotte Zwerin, 1969).
Another Maysles brothers documentary. The subject: traveling bible salesmen! By the time the film is halfway through, you're rooting for the poor sons of bitches to wring every last penny out of all those sorry underpaid working-class wretches who can't afford the clothes on their backs, let alone big tacky $50 bibles. Undoubtedly a major influence on Daniel J. Harris' mean-funny The Bible and Gun Club (1996), which I saw on Sundance several years ago.