I reached out to anthrodesign to vote for this topic because it obviously relates to anthropology and design. But I also decided to reach out to IxDA, because I think this topic is relevant for interaction designers whose work involves web sites used by the general public (less so for software designers).
For example, if you are an interaction designer for an outdoor product site like Patagonia.com or REI.com, doing a discourse analysis of outdoor discussion forums (e.g. Backpacking.net) can help you identify the most significant category-specific navigation options and attribute filters based on frequently expressed customer needs. Going beyond the typical Brand, Price, Style filters is critical for e-e-commerce, because they don’t accurately reflect how people shop in many categories of merchandise.
Every area of merchandise has its own most prominent attributes that the bell curve of shoppers are hunting for as an initial cut before scanning the virtual shelves, and are frustrated when they don’t find them. Digital ethnography can decisively solve the facet/attribute/filter question that many merchandisers and interaction designers face on a regular basis.
This research method doesn’t replace in-depth interviews (for example, see http://vimeo.com/12526177 for millennials shop-along video), but it is a useful tool in the arsenal of UX strategy.
