Stiftung Warentest
Since more and more companies do not wish to be surveyed and refuse to provide the information requested, Stiftung Warentest now also evaluates databases and business reports, as well as relying on private providers as sources of data. In addition, specifically trained freelancers often act as customers. Mystery shoppers for example played an important role in testing out the investment advice services of banks (issue 08/2010) and the statutory health insurance providers (issue 09/2010).