You can have cards printed with boxes to check easily so people will spend the time to answer your questions. Manufacturers use surveys with warranties. Appliance makers often include a few questions along with the warranty that the consumer sends back. Most major manufacturers have their own teams of product testing. Toymakers bring in children and watch their reactions.
Book publishers have people look at covers and decide which they'd buy.
Even the car manufacturers run surveys and opinion testing on style and pricing. Be familiar with the people who buy your product or service, and have a full understanding of the general competition and the full scope of marketability.