However, online tools such as Zoomerang , Constant Contact or Survey Monkey make it easy to devise a reliable questionnaire. Three to four hundred respondents will provide reliable and projectable data. Even if you don’t, companies like Zoomerang will give you access to a huge databases with highly detailed demographic data. How to Get Started on Cheap and Powerful Customer Studies Unless you understand your customers, you risk painful marketing missteps. Because we know that effective content marketing depends on a thorough understanding of your customers,