It appears to me that minorities have a better chance of getting to complete the surveys than Caucasians because the sponsors are looking for a cross-cultural sampling of respondents, at least where ethnicity is concerned. Also having children 18 and younger seems to be more acceptable, as they ask that all the time. I am not sure on the household income, as everyone has to buy products regardless of income-- perhaps you buy different types of products at different financial stages, but there are always the basics that all people need. I agree that it is very frustrating to spend a lot of time on a survey only to be kicked off.