> Especially knowing that most people probably don't need the best answer 100% of the time.

More: probably don't know if they've got a good answer 100% of the time.

It is interesting to note that this trickery is workable only where the best answers are sufficiently poor. Imagine they ran almost any other kind of online service such email, stock prices or internet banking. Occasionally delivering only half the emails would trigger a customer exodus. But if normal service lost a quarter of emails, they'd have only customers who'd likely never notice half missing.