What is ethnography not good for?
Product testing and ad testing: if you have a product you want to test, focus groups are cheaper. If you want to find out the answer to a highly specific question about a well-defined kind of person, and if the answer requires a means-based statistic, larger-scale sample surveys may be best. Ethnography is not good for answering questions where everyone is already quite certain they already understand what makes things tick. This is because ethnography usually discovers some aspect of the ticking that had not been accounted for in the past, some variable that does not vary by it self the way it should, or some set of questions that could be asked but had not yet. So ethnography is not good when questions are set in stone, when knowledge about variables smells more like religion than science.
