'Claudia' is neither a real name nor an owner who puts a room at the service of the collaborative economy. It is a pseudonym used by a transnational company which manages short-rentals apartments: 211 Airbnb listings in Madrid, 138 of which are in the city centre. This paper's main arguments are based on the fact that Madrid city centre is experiencing a process of airbnbisation which is driven by professional actors specialized in the short-term rental business. The analysis of this model includes an in-depth examination of the professionalization, concentration and monopolization of Airbnb in Madrid, from a temporal and territorial perspective. The paper concludes that Airbnb in Madrid is dominated by professional actors specialized in the business of renting apartments as short-term rentals, who mainly operate within the city's Central District, and whose activity does not comply with the principles of the sharing economy. This model has more to do with traditional forms of accommodation than with new hospitality models based on the sharing economy principles, and generates negative impacts on the economic sustainability of the city and its inhabitants.