At Pandora, Every Listener Is A Test Subject

Sarah Young listens to Pandora constantly. From the moment the 27-year-old hairstylist wakes up in the morning, she's tuned into one of the service's infinite personalized radio stations. When she's finished getting ready, she flips her laptop shut and heads into work, where an iPad streams Pandora all day. On her way to and from the salon, she listens to the "'90s new wave" station on her phone. Lately, she's noticed more repetition. "One time, they played this Portishead song five times in three hours," says Young. "Things seem to get more repetitive in the mid-afternoon." Young doesn't know it, but she's a lab rat.