Airbnb is charging hosts an additional 12-15% fee for each booking if their guest found the listing through Google advertising.
The sharing economy accommodation provider quietly introduced the "trial" programme in early-August.
But there's a lot more to it than that.
The All About Airbnb blog has many of the intricate details as to how it affects hosts, but essentially Airbnb has started a process by which it will advertise its listings in specific cities around the world.
If a user in Google clicks on the ad they will be directed to a page featuring properties in the UK capital.
"To help cover the cost of these advertisements the host fee is increased, but just for the first-time reservations that happen as a result of the ads," Airbnb says.
Perhaps one of the most curious elements to this story is that hosts must "opt out" of being included in the listings (which include the additional fee).
Still, Airbnb says it will only charge the fee when it establishes through tracking that the guest found the property after clicking on the Google ad.
The existing search and booking process on the website will not be tweaked or affected by the introduction of the trial.
"The most frequent request we hear from hosts is that you want more bookings. To make this happen, we need to make sure that more people hear about Airbnb.
"As an organization, we're spending as much as we can on marketing, like our first TV commercial, Never a Stranger, and many types of online advertisements.
"But there’s no end to the amount of advertising that can be done. By charging a higher fee - but only when hosts are directly profiting as a result of the advertisements - we can finance additional advertising.
As the All About Airbnb blog notes:
"The normal 3% host service fee is something that most of the hosts don’t notice, don’t really care about or are even happy to pay for the service received.
"But a four to five times increase does make a difference, since it significantly impacts the amount hosts will end up receiving in their pockets."
Where the story gets a little bit misleading is in Airbnb's assertion that "these online ads are just a trial" and that it will be evaluating the results.
The element that is new and under experimentation is actually just the taxing of hosts when they participate, solely because Airbnb has been using paid keyword advertising (aka "online advertising") on Google for quite some time (it even features as a case study on the Think With Google website).
Some Airbnb watchers predict hosts will more than likely not opt out of the ad tax programme, despite its unpopularity, given that they may still consider the opportunity to attract more bookings worth the increase in host fees.
"Increasing revenues overnight might indeed allow the company to drive more potential guests to the site… but at what cost?" ponders All About Airbnb.