I'll recommend Nicholas Taleb's "The Black Swan" to the authors of this prediction tool. Statistics cannot be used to "predict" future behavior of a complex system.
Statistics cannot be used to "predict" future behavior of a complex system
They certainly can, and commonly are! Think of weather prediction, Bayesian diagnostic systems, Google's statistical translator and spell checker, etc etc.
Taleb's point is that they fail sometimes - perhaps more often than you think - and so you should be very careful in placing bets on statistical predictions.
In this case the cost of a failed prediction is very low, and a successful prediction is worth quite a lot, so it is a net win for Google.
