The success of Fifty Shades of Grey let the world in on the e-reader's dirty little secret: its ability to conceal less than respectable reading matter. But are we really only downloading mommy porn and cheap thrillers? I asked commuters on the London underground to tell me what was on their e-readers.
Inda, 48, payroll manager: Grimm's Fairy Tales Inda loved the brothers Grimm as a child and fancied a change after Stieg Larsson's Millennium trilogy, which she also read on her Kindle.
Ross, 24, works for an internet startup: Catching Fire by Suzanne Collins Having enjoyed the Hunger Games film, Ross is working his way through the books, which he borrows via Amazon Prime.
Cheryl, 45, PA: Me Before You by Jojo Moyes A friend's recommendation, although Cheryl's not enjoying it that much. She likes her Kindle but prefers the "touch and feel" of paper books.
Jackie, 28, office manager: Wedding Tiers by Trisha Ashley Jackie wanted something "nice and easy for the commute" and had read Trisha Ashley before. When she likes a writer she wants to read everything they've written and finds this "easier and cheaper" to do on a Kindle.
Nicholas, 69, works in shipping: The Eighth Scroll by Dr Laurence B Brown Nicholas downloaded The Eighth Scroll because he liked the title and it was only 70p. For favourite authors such as Wilbur Smith he'll pay "up to £5.50". He shares his Kindle with his wife, who prefers "silly, girly books".
Aidan, 36, policeman: The Rum Diary by Hunter S Thompson Aidan saw the film and wanted to read the book. He was the only person in my sample using a Kobo.
Paul, 50, product manager: Seven Troop by Andy McNab The only person reading on an iPad. He gets through half a dozen ebooks a month: "much more than I read before".
Emi, 26, internet entrepreneur: The Start-up of You by Reid Hoffman Most of the stuff on Emi's Kindle is business-related but he also reads novels. Next up is Chad Harbach's The Art of Fielding. Price isn't an issue: "I'll often spend £100 on clothes, so £100 on 10 ebooks is pretty reasonable."
Four people refused to tell me what they were reading, including one man surrounded by schoolchildren who went bright red and clutched his Kindle to his chest.
