Mass market paperbacks have had little growth over the past five years. According to the Book Industry Study Group, sales rose only 2.6% between 1999 and 2003, moving from just under $1.7 billion to $1.74 billion. Growth has come entirely from price hikes, as unit sales dropped 6.4%. BISG forecasts paperback sales to grow at a 2.3% compound annual rate over the next five years.