By James R. Hagerty

Harry Hoffman, a former FBI agent, learned salesmanship at Procter & Gamble Co., a maker of soap and toothpaste. Later, as chief executive of the Waldenbooks chain from 1979 to 1991, he used some of the same mass-marketing techniques to sell books.

Dominating his stores' displays were blockbusters from the likes of Tom Clancy or Danielle Steel. Self-help manuals, get-rich guides, greeting cards and gifts also featured prominently. Literary works were relegated to the margins.

Under the leadership of Mr. Hoffman, who died May 20 at the age of 92, Waldenbooks surpassed B. Dalton/Barnes & Noble to become the largest U.S. bookstore chain. The number of Waldenbooks stores jumped to about 1,300 when he retired from 540 when he arrived. Mr. Hoffman used his growing power to squeeze publishers for bigger discounts.

The Wall Street Journal in 1988 called him the most powerful man in American book publishing.

He gave advice to publishers on cover designs and marketing. Waldenbooks promotional decisions could make or break a book. Unknown authors wrote to him for tips.

With little apparent success, he urged publishers to offer shorter books. Readers wanted books they could finish in a day, Mr. Hoffman said. If publishers insisted on brevity, he argued, authors could write two or three books a year instead of one.

David Godine, an independent publisher, told The Wall Street Journal that Waldenbooks catered to mediocrity. "When a company makes book selections based on ad budget and printing size," Mr. Godine said, "they're cutting off the main responsibility of people in publishing, which is to find and nurture new talent."

Mr. Hoffman shrugged off criticism of his marketing techniques. "The whole industry is lethargic in trying to reach the consumer," he said.

By retiring early in 1991, at age 63, he avoided the eclipse of bookstores by Amazon.com and other online sellers.

Waldenbooks was owned by Carter Hawley Hale Stores Inc. when he joined and sold to Kmart Corp. in 1984. Borders Group Inc. later owned Waldenbooks. The stores were liquidated in 2011.

Henry Theodore Hoffman III was born Oct. 28, 1927, in Brooklyn and grew up in Freeport, N.Y., on Long Island. His mother taught kindergarten. His father was a door-to-door encyclopedia salesman.

The Army stationed him in Japan after World War II. At Colgate University, he earned a degree in history. While he worked as a lifeguard at New York's Jones Beach, a colleague mentioned opportunities at the Federal Bureau of Investigation. He worked for the FBI from 1951 to 1954 before joining P&G, which assigned him to sell its products to grocers in New York.

"In 60 days, I had gone from carrying a gun to carrying soap," he told the New York Times in 1986. "It was such a drop in prestige that I got an ulcer." Promotion to a managerial job eased the pain.

He later worked at a library-supply company and then joined what became Ingram Book Co., which he built into a leading wholesaler of books. His success there attracted the attention of Carter Hawley Hale, which recruited him to head Waldenbooks.

While running Waldenbooks, based in Stamford, Conn., he lived as much as half the year on a boat docked on Long Island Sound. Retirement gave him more time to sail, particularly in the Caribbean.

Mr. Hoffman's marriage to Norma Jean Olson ended in divorce. He married Kathie Petersen in 2012. He is survived by her, three children, five grandchildren and five great-grandchildren.

Jan Keeling, one of his daughters, recalled a sailing trip with him. "There were other sailboats around, everyone sailing peacefully. I noticed when we pulled past another boat and got ahead of it, Dad would say with satisfaction: 'We beat him!' I thought it was funny because it hadn't occurred to me that we were racing."

Write to James R. Hagerty at bob.hagerty@wsj.com