Writing in The Independent, Arts and Media Correspondent Anthony Barnes reveals that "misery is the book world's biggest boom sector." He's talking about the advent of the misery memoir--childhood or spousal abuse, addiction, poverty, etc. etc. In the UK, more than than 10% of the top-selling non-fiction titles were in this category. In fact, Waterstone's book shops have added a "painful lives" section.
Barnes quotes punblisher Carole Tonkinson: "They are appealing mainly to women with young children, so for readers there is a material pull to these stories, which often have a child in peril, and a lot of the covers feature children." If you want to sample the misery, some of the top titles are "Behind Closed Doors" (Jenny Tomlin), "Don't Ever Tell" (Kathy O'Beirne), and "Ghost Girl" (Torey Hayden).
I've often said, jokingly, that if I ever write my life story I will call it "My Parents Ate My Pets and Other Reasons I Turned Out This Way." Maybe I should start working on it for real. (The clue is in the photo. Don't ask.)