Brands became aware of the necessity of implicating their consumers in the communication they sustain through paid, earned and owned media channels, thus making it a must in their digital marketing strategy. Consumers` behavior nowadays shifted; as they tend to spend a lot of their spare time getting informed online before any purchase. The main cause for this paradigm shift is the internet, as it enabled consumers to search information and compare between competing brands, before any purchase; therefore establishing itself as one of the most influential brand  touchpoints. Using the public as brand ambassadors is a common trend nowadays, yet their reaction to the brand communication varies based on cultural, social and economic factors. This paper aims to clarify what brand communities are, how they come to be - are they built from the ground up or do they exist and just need to be tackled with-, common traits of successful communities, what brand objectives can be accomplished with these groups, what role does social media play in their development, the ideal mix between online and offline actions, types of members we encounter in the online communities environment and their segmentation, best research methodologies to monitor these groups and lessons learned from established brand communities.