focus on customers who patronize any one particular bank. A convenience sampling technique was selected due to its cost and time efficiency. The final questionnaire was administered by three trained research assistants, who distributed the document in the central business district of Bangkok. Respondents were personally approached at shopping malls, office buildings, entertainment establishments and other high-traffic locations. The research assistants were instructed to administer a minimum of 15
questionnaires at each location. This restriction was set to avoid the possibility of receiving responses that were related disproportionately to a small number of banks
because of the effect of payroll services used by their employers.