Generally between 100 and 1000. Of course, it is better to have data than no data, and more data samples are more conducive to the authority of data.

According to the experience of market research, a survey with strict requirements on market potential needs a larger sample size, while a survey with less strict requirements on quantity or product testing, product pricing and advertising effect needs a smaller sample size. ?

The sample size is related to the number of people or units included in the survey. Determining the sample size is a complex problem, which requires both qualitative and quantitative considerations ~ I want to investigate the network to make the investigation easier and more convenient!