The tent circuit was rapidly heading for extinction by the time this documentary was made, so in addition to being one huckster's self-exposure of his skullduggery, it is also an examination of a subculture which would soon cease to exist (or at the very least be transformed into something wholy unrecognizable from its forebears).
Interestingly, even though the movie depicts the tent revival as being primarily a Southern phenomenon, the revivals shown in the movie took place (if I am recalling correctly) in California & Fort Worth Texas.
Certainly the notion of saving souls for fun & profit is nothing new, but Marjoe Gortner's candor about exactly what he is doing, including the process of exposing himself as a fraud, is a tad unsettling. Both the subject & the filmmaker know that Marjoe's reasons are far from altruistic, and each is using the other for his own purposes. The result is, at times, a rather surreal experience. Marjoe is revealing himself, but in many ways he isn't. We can never really be sure in what he believes, if anything. I suspect it wasn't so much conscience as it was a practical business decision (the tent circuit had been slowly waning since the end of WWII, when the formerly-rural American population once and for all became urbanized)) as he recognized that there were more lucrative media in which he could utilize his talents. Given his upbringing, not as a child but as a gimmick to be exploited, it would be amazing if he has a conscience at all.
Did it make a difference? Apparently not much of one, since Benny Hinn appears to be quite comfortably well-off. People will believe what makes them feel most comfortable. It wouldn't surprise me if some people believed that Marjoe made these outrageous claims of being a fraud only because Beelzebub somehow tricked him into it. For all I know, they may be praying for Marjoe's return to the fold, even today.