Airbnb (ABB) offers short-term rentals for tourists via an online-market platform. In contrast to traditional holiday lodgings the flats are usually residential apartments or rooms, offer fewer services and are therefore mostly cheaper. The phenomenon of ABB can nevertheless also trigger spillovers to non-participants and is currently being debated extensively in several German cities. The prevailing view: The urban housing markets are concerned with a diminution of housing supply and increasing rents. The central point thereby is, that due to ABB a large part of residential flats is removed from the housing market. Several providers divert their flats illegally into permanent holiday flats and do not just offer the flats occasionally as is intended by the share economy. Berlin is the largest ABB-market in Germany and especially here individual buyers have discovered the conversion from rental flats into holiday flats as a specific investment scheme. This paper aims to analyse the coherence between the ABB-density and housing rents in the different neighbourhoods of Berlin with a simple 1-W ANOVA. Furthermore, the web data of ABB is analysed with respect to illegal usage.