Barnes & Noble, the world’s largest book retailer, has decided to sell O.J. Simpson’s book “If I Did It” in its stores, reversing an earlier decision to offer the controversial title only on the Web.

“Our customers are asking for it. We have been monitoring pre-orders and decided we had enough” to put the book on retail shelves, company spokeswoman Mary Ellen Keating said on Thursday.

“If I Did It,” in which the former U.S. football star offers a hypothetical account ...