This 2015 New Yorker story describes the rise of mass-market-paperback book publishing. It also has some interesting images of classic books, such as the Great Gatsby, that were republished with pulpy covers to try to appeal to different readers. The author of the piece is Louis Menad, a literature professor at Harvard and cultural critic. I found this piece on the New Yorker’s website: http://www.newyorker.com/magazine/2015/01/05/pulps-big-moment