When iTunes first released its shuffle feature received a slew of angry emails. The complaints came from customers who claimed the feature was broken because, when they clicked the “shuffleβ button on their *NSYNC album, the tracks sometimes played in order. People felt cheated. How could a random algorithm produce three songs in the same order as they appear on the actual album? Random should mean 7, 11, 3, not 1, 2, 3, right? Except that when song selection is truly random, each song has the same probability of playing each time the current song ends. Sometimes that means 7, 11, 13, but sometimes that means 1, 2, 3 instead.
In response, iTunes changed their randomness algorithm to avoid such sequential ordering. The new algorithm feels more random to us humans despite it being objectively less random.
Excerpt from: Blindsight: The (Mostly) Hidden Ways Marketing Reshapes Our Brains by Matt Johnson and Prince Ghuman