This article aims to analyze different types of Social Networks, its purpose, success and evolution, and also its advantages for people and businesses in particular in Real Estate mediation in Portugal. This article includes some research related to the use of Social Networks and its relationships with Real Estate. First the social networks and issues related to investment and Marketing relations are analysed, structured and classified, and it is also analysed the Real Estate business. Then there are presented some statistics based on data according to Social Networking use in Real Estate companies in Portugal and in particular, the use of Facebook. Finally, some conclusions of this study are presented and highlighted the main limitations of this research as well as some recommendations for future studies. According to statistics made by Real Estate companies in Portugal, in a universe of 3231, and given a sample of about 500 companies in the Real Estate business, 15% have their own sites and in these, Facebook subscription is over 12%, 4% on Twitter, 1% on LinkedIn, and no more than 1% on YouTube. By Adding and adapting technologies and new trends like Social Networks and using the Internet, we can expect a better understanding of consumers and new ways of doing business and new business opportunities. There are few articles referring to Social Networks and Real Estate and in Portuguese reality this is even more uncommon. This kind of researches should be more frequent and compared, when possible, with other countries and other situations.