The closest I ever came to being in a cult was back in the early seventies when a joined a board gaming club called "Sparta". It had all the trappings of a cult - an omnipotent, almighty (in his own mind) leader, uniforms, mega serious attitudes, and fanatical followers. Things came to an end in 1974, though, when the leader was kicked out by assistants who weren't as loyal as he though they were. Them's the breaks!!!
shareNot a religious cult, but as an inexperienced youth in the 1990s, I once thought I had a job, joining a "direct marketing" (read: door-to-door canvassing) outfit that had a charismatic leader, morning rev-ups, the unreasonable demand to put all your time in (probably something like 10 hours? I can't remember...) I think it was 6 days a week, and still getting paid next to nothing on a bad day and not so great on a "good" day either, etc. I wouldn't be surprised if places like that are still in operation now.
I've seen two imDb reviews that specifically reference "network marketing" being exactly what this film is based on. From what they described, Zack is a network marketer and his whole thing that he does is about hawking the Rebirth "not-a-product" line. They say that despite some exaggeration here and there, it's a lot like real life. Scary!