limitations of random sampling
Quick Answer. Although simple random samplings are a common research method, they are expensive to use, extremely time consuming and difficult to organize. A simple random sampling requires a complete list of all members of the target population so that the sample is a real representation of the larger group. Each individual in the population has the same chance of becoming part of the sample. All possible combinations of the sample are equally likely to occur, as well.
Missing Population Segments. Simple random sampling can give you a very accurate picture of how your slogan performs with the average person, but it won't give you detailed information about specific groups of people. For example, suppose you want to know how your candy bar slogans work with tennis-playing single men ages 18 to 45.