Ethnographic research is very enlightening to product managers, engineers and developers of products. The research involves interviewing the user to understand why they used the product the way they did. Interview questions should attempt to understand why features and alternative methods of your product were not considered or used.
Ethnographic research is a real "outside-in" approach to researching users' opinions and demands. No one can argue with it. The information is coming directly from the user while using your product, not while imaging or recalling how they once used it. Marketing Excellence has been using this type of research for many years. We have been very successful conducting ethnographic research with software and computer-based products as well as products that are complex to operate (electronics), personal (garments/clothing), or seldom used (home improvement tools for the do-it-yourselfers).