Sometimes web survey companies like Pinecone Research will target people in their database for a preliminary screening to see if they meet the minimal requirements to enter the study.
The respondents are asked some basic questions regarding their buying habits for particular product
based on the survey and if the respondent asks the questions in a favorable manner then they will be asked to complete the full-blown survey if not the questionnaire will end there.
Should they go on to complete the survey, they usually receive monetary compensation and in some cases a client might request that the respondents receive a sample of the upcoming product and offer their feedback on this new product on another survey.
This usually happens when the respondent really fits the target market and where a particular product and manufacturer feel that this type of customer would be both likely to buy the product and will offer the most important feedback of all. The respondents get to keep the free items and they also receive monetary compensation as well.