there were more female than male informants,aged between 36 and 50,with 43.8% were married, 66.0% holding a bachelor's degree, 54.8% were government officials and state enterprise employees, 44.0% having an income ranging from 15,001 to 25,000 bath a month, 30.5% having membership status as the buyer and independent business owner (IBO) who received a special discount, 43.0% having an average purchase of 2,001-3,000 bath a month,30.5% living in a family with four members, and 66.3% living in an urban area.