What is there to be baffled about?

I offer to sell 70 shares at a ridiculously low price. You assume, or are scared into believing that is the price and the sky is falling, so you sell 30 more at that price.
My cohort buys the whole lot and we divide the 30 between us, laughing all the way.

Sorry for the simplistic answer, but that is the only thing that makes any sense and it has to be sensible, they are shrewed to no end.

If there is any confusion, it is with why are there people who fall for the scam knowing the writing on the wall. Surely they have to know it.