Airbnb is great, right? It works out much cheaper than staying in a hotel. You also get a far more homely environment, often with the benefit of a full kitchen and separate living room with a TV and entertainment.
With their handy review system you can read up on previous guests' experiences before you book, and of course leave your own comments and interact with the hosts.
Aside from these obvious perks it gives an extra income to householders who find themselves with empty rooms while they're on holiday.
However, an independent website called Inside Airbnb explores how the company works in different cities around the world. It found that in London 64% of the listings for short-term rents were in fact available for more than 90 days a year. As of 2015 this is against the law.
The maximum stay allowed for a short let is 3 months, or 90 days calendar days. Owners who rent for longer need to apply for permission, however local councils are often reluctant to grant it. According to an investigation by Vice, Camden council's reasons include the potential disturbance to neighbours and the harm this can do to the permanent housing stock.
This last point is important because if properties are being rented "full-time" for short lets, they're kept off the rental market for those who need them, worsening the already critical housing problem.
Inside Airbnb also found as many as 10,000 hosts listing more than one property. This means they're more likely to be running a business, and not simply renting out their empty rooms while they're on holiday, which was the main purpose of Airbnb in the first place. Consider how high that figure is given that as Airbnb claim, there are 24,000 active hosts in the capital.
There is obviously a lot of money to be made here. A clear example are a new breed of companies called Airbnb management services. Do a quick Google search and for London alone you'll find pages and pages of them. They take care of things like exchanging keys, laundry and cleaning - some will even snap professional photographs for the listings. While they take a cut of the profits the homeowners can sit back and relax.
It's a very muddy area. Technically Airbnb management services aren't breaking the law, but as part of their remit is to guarantee maximum occupancy for the homeowners, it all starts to sound a bit dodgy. Yet it also makes sense - Airbnb is worth £17 billion.
Is Airbnb great for giving extra income to homeowners? Or is it making the rental crisis worse? Leave us a comment on Twitter