The point is that if a book that had been published three years ago started to sell twice as many all of a sudden it probably wouldn't even get noticed. People wouldn't be tracking it. The system has cleaned up its act an awful lot but the best-seller list system is not an entirely foolproof thing.
Terry PratchettAziraphale collected books. If he were totally honest with himself he would have to have admitted that his bookshop was simply somewhere to store them. He was not unusual in this. In order to maintain his cover as a typical second-hand book seller, he used every means short of actual physical violence to prevent customers from making a purchase. Unpleasant damp smells, glowering looks, erratic opening hours - he was incredibly good at it.
Terry PratchettYou couldn't say 'I had orders.' You couldn't say 'It's not fair.' No one was listening. There were no Words. You owned yourself. [...] Not 'Thou Shalt Not'. Say 'I Will Not'.
Terry Pratchett