2. A major advantage of mail panel research is that the cost is low especially since bulk postage is cheap. There is also no interviewer bias and the respondents can answer at their convenience. Furthermore, mail surveys may be long so a large amount of information can be obtained. A major drawback of this kind of research is that the surveys can be returned after several months; thus, a cause of delay in the research. There is a low response rate with this kind of survey. This kind of research is not suitable if the issues in the survey need clarification such as very technical topics.
I think NFO used a mail panel because it is less costly. Since NFO has a set of panelists already, they did not have to gather a new group for the research. This means less effort and expense on their part. Moreover, NFO can reach a larger population with this kind of survey because it does not require personal