Not disputing they're going to make a lot of money from this, obviously when they wake up tomorrow morning they're each going to have tens of thousands more than they had when they woke up this morning. In that sense it "works".
But relative to other models the "pay what you want" is a terrible failure - any of those games could have singlehandedly grossed $30,000 to $60,000 from the number of sales they've had today, and that's going to lose a big chunk to advertising but still make them a lot more than $1.66 a sale.