The chapter presents a comparative analysis of trends in the peer-to-peer lodging and their impacts on the lodging industry of the metropolitan regions of the Greater Los Angeles, California, USA, and Southern Europe (Athens, Greece; Barcelona, Spain; and Vienna, Austria). The main research question is whether the emerging peer-to-peer lodging platforms, part of the exploding sharing economy, are competitive or complementary to the traditional lodging industry. Data was obtained from secondary research and collected in 24 field interviews. The study found variations in the complementarity/competitiveness equilibrium, depending on the market segment in hospitality industry and regulatory environment. The chapter draws recommendations for hotel competitiveness.