The Financial Times Germany once spoke of ""Star Wars"" and placed the adjective ""dirty"" (Financial Times Deutschland, 2012) in front of it. The article featured review sites where customers comment and rate the performance of different companies. The German edition of the Financial Times was shut down a few years ago, but what it had called ""the dirty war of the stars"" has gained a high degree of importance. People tend to base their decisions on electronic word-of-mouth, that is the wisdom of crowds, in the absence of personal referrals, that is the traditional word-of-mouth.

Today crowd-sourced online review sites are available for nearly all industries, but the real estate industry is still underestimating the importance of the topic.

Currently, in many parts of Germany real estate companies have problems to acquire properties. Therefore, an excellent online reputation is crucial. Companies who have negative reviews on the Internet will not be able to compensate this with a good marketing. Consumers increasingly use such review sites, or apps in the absence of personal recommendations, whether in travel (Hotel.com, Tripadvisor.com or Booking.com), in the analysis of potential employers e.g. Kununu.de, or they use cross-industry portals such as Yelp.de.

The purpose of this paper, based on a national empirical survey, is to examine the awareness of the real estate industry concerning these sites, furthermore the paper discusses the strategic options of real estate companies concerning crowd sourced online review sites.