WonderBranding talks about cultural anthropology as a way of getting market information:

Watch how she not only uses your product but also how she doesn’t … is she unaware of an advantage your product offers but you keep forgetting to tell her about?  Or is there something you need to change?  Proctor & Gamble is having a great success with an ongoing series of “immersion” studies.  They've gotten important feedback from surveys, but it was only when they had a group of mothers wear headgear cameras throughout the day (giving them a bird’s eye view of what the mother sees) that they discovered new ways of packaging diapers and baby wipes that made them easier to use.  Information like this is the reason P&G profits are on a steady incline.

I wonder though - are the people who are willing to wear headcams truly representative of your target market? And, does the fact that they know that they are going to be watched change their behavior? I'm not sure there's a better way to gather the sort of information WonderBranding wants, but I think that the data gathered this way should have a few caveats attached.