One source of research that you can trust is the government. The census studies are large and are based on activity rather than surveys. Their results can be relied upon and much of the data is now available online and can help you to gain tremendous insights, even on a local level.
Census Factfinder, posted in folder 3 talks about the website, which lets users access detailed socioeconomic and demographic information for areas that they define. (This website was retired in June 2020, and the data can now be found on the census.gov site.)
Please access and use the data yourself by picking a zip code and telling us 20 descriptors/differentiators that describe its inhabitants and what business might be successful marketing in the area based on that data.