Like Steve Jobs, Tim Cook is known to read and sometimes respond to customer emails from time to time. In the most recent offbeat example, a Reddit user detailed how he once emailed Cook regarding the less than stellar music that would play when he was on hold with Apple. To his pleasant surprise, Cook responded and the music was replaced with something more pleasant to the ears.
I once sent Tim an email about the quality of music while on hold with Apple. It was super low quality, therefore an upbeat rock song sounded like pure distortion and really aggravated me because I was on hold for 20+ minutes for something so simple (iPhone didn't turn on, needed to set up a repair as in my country no Apple Store = have to send it to another country).
Much to my surprise a lady from Cupertino called me up the next day, saying she'd received a concerning email from Tim about ugly distortion hold music while on the phone, that Tim had tested this himself and agreed that something had to be done. She assured me that the hold music would be tested to make sure it sounded pleasant on all types of phones and connections.
The next time I called Apple, the hold music was indeed very pleasant.
Cook has previously stated that he receives upwards of 800 emails a day and that he reads most of them.