The decrease in the typical duration of tourists' stays in Portugal, which has gone from 6.7 days to 4 days in the past decade, is likely to affect various aspects of the country's tourism infrastructure, including its airports. Additionally, there has been a problem with noise pollution in residential areas due to touristic establishments like bars and nightclubs.
I would imagine via AirBnB or short term rentals in general. Last time I stayed in Lisbon I stayed in a converted apartment, via AirBnB. It certainly puts pressure on the long term rental market.
