When I requested my personal information from Amazon this month under California’s new privacy law, I received mostly what I expected: my order history, shipping information and customer support chat logs.
But tucked into the dozens of files were also two Excel spreadsheets, more than 20,000 lines each, with titles, time stamps and actions detailing my reading habits on the Kindle app on my iPhone.
I now know that on 15 February 2019 starting at 4.37pm, I read The Deeper the Water the Uglier the Fish – a dark novel by Katya Apekina – for 20 minutes and 30 seconds. On 5 January 2019 starting at 6.27pm, I read the apocalypse-thriller Severance by Ling Ma for 31 minutes and 40 seconds. Starting at 2.12pm on 3 November 2018, I read mermaid romance tale The Pisces by Melissa Broder for 20 minutes and 24 seconds.
And Amazon knows more than just what books I’ve read and when – it also knows which parts of them I liked the most. On 21 May 2019 I highlighted an excerpt from the third installment of the diary of Anaïs Nin, the data shows, and on 23 August 2018 at 11.25 pm, I highlighted an excerpt from Leslie Jamison’s The Recovering: Intoxication and its Aftermath. On 27 August 2018, I changed the color of a highlighted portion of that same book.
Other habits tracked included the times I copied excerpts from books into my iPhone’s clipboard and how often I looked up definitions of words in Kindle’s attached dictionary.