 In the 1960s and 1970s, shopping-mall chain bookstores B. Dalton, Crown Books, and Waldenbooks came to the forefront with a business model of selling newly published best-sellers with mass-market appeal.They used the best-selling status of titles to market the books and not just as a measure of sales, thus placing increased emphasis on the "New York Times" list for book readers and book sellers.As shown in the graph below, the number of titles achieving the number one spot has grown consistently over the years, ranging from fewer than 10 in the 1970s to the high thirties in the current decade.