Booking.com, the online travel agency giant owned by Priceline Group, has begun listing homestays. These accommodations don't come from Booking's traditional vacation rental inventory.
A majority of the 5,100 homestays are also not available on Villas.com, the brand's sister site. (Villas.com is a self-catering lodging counterpart to HomeAway, the largest vacation rental platform.)
The fresh content can be found by clicking a new "homestays" filter that has appeared on the left rail of Booking.com. The homestay filter option appears under "Property type" after a customer has run a hotel search and is looking to refine the results.
Design tweaks
If Booking.com is committed to the "homestay" category, it is entering the turf of Airbnb, the current market leader in short-term rental customers.
In another Airbnb-like move, Booking.com is testing a design that makes pictures of properties much bigger and that has more intuitive drop-down menus and less visual clutter.
Here's the template being tested that echoes the Airbnb user experience:
Here's the current one:
A work in progress
"Homestays" is now a category that Booking.com users can filter on. It's distinct from "Apartments," "Holiday homes," "Villas," "Guest houses", "Bed and breakfasts," "Hotels (with kitchen)," and "Hostels."
Booking.com has not officially announced this new category. [UPDATE 15 July: More information from Booking.com, here: "How to list your Airbnb-style homestay on Booking.com"]
But a Tnooz review of the properties called "homestays" finds that they tend to be places where a guest is staying at the same time as the owner-residents and where there isn't usually a promise of breakfast.
That said, the category of "homestay" isn't strictly defined.
To prove this point, Tnooz ran a search for a visit to Rio de Janeiro in May 2016. Booking.com listed 34 "homestays." Villas.com only listed 2 "homestays."
One of Booking.com's homestays is a three-room Rio apartment owned by "Tomas and Brice," with a private room. The bathroom, living room, and kitchen are shared with the owners and guests using the other rooms.
Significantly, Booking.com is not requiring a credit card in advance to secure a homestay in many of the listings Tnooz saw. That makes it different from many Airbnb listings.
For instance, a homestay in the Copacabana district of Rio de Janeiro is avialable as private room with a kitchen shared with the owners.
One could make the argument that Booking.com doesn't care too much about having a strict definition of what a "homestay" means.
For instance, several of the properties in Hoi An, Vietnam, were (as of publication time) traditional apartments or guesthouses.
A case in point: Hoi An Luna Villa Homestay is listed both as a vacation rental on Villas.com and it appears as a "homestay" in Booking.com's new homestay section.
But it is merely a standard vacation rental. Perhaps having the word "homestay" in its name and description has confused a tagger at Booking.com.
Then again, maybe Booking.com feels that "homestay" means different things to different travelers -- and that that is okay.
In other words, rather than try to categorize properties too precisely, Booking.com may have decided that "homestays" is a growing search term on its site and that it wanted to let users filter for "homestays" -- even if the inventory it lists under that name is something of a grabbag.
Is it a "homestay" or a "vacation rental"? Consumers are often confused what to call what they're looking for.
Booking has added "homestay" to its list of 22 lodging descriptors, which are broken up under headings like "chalets" and "country houses" and "guest houses". Click on the listings in any of these sections, and you'll often find that properties are tagged under multiple categories.
By listing a place under multiple categories, it may appeal to the most number of users, who may not know what to call what they're looking for.
Another rival for Airbnb
One thing does seem likely: Booking.com appears to be readying for battle against Airbnb.
Airbnb may have provoked this battle. Many properties on Airbnb are now vacation properties rented out by full-time landlords who do not live in the properties they rent.
Take a look at "Paissandu 102". It's the name of lodging in apartment 102 in a skyrise at 221 Rua Paissandu in Rio de Janeiro.
You can find 102 Paissandu under "apartments" on Booking.com.
And you can also find 102 Paissandu listed on Airbnb.
Is it a homestay or a vacation rental?
Who knows? It's one of 378 "homestays" listed among 2,278 accommodations in Rio on Booking.com. (About 1,683 of the other options were "apartments" and were cross-listed on Villas.com.)
For a broad search for May 2016 dates in Rio, Booking.com turned up 781 apartments. Villas.com turned up an identical 784 apartments for those same dates. That's because they're using the same content.
Some of that apartment content already overlaps with Airbnb's.
Note: We have sought comment from Booking.com and will update this article when we hear back.
UPDATE: A spokesperson says:

"To meet the needs of our customers, Villas.com offers customers holiday rental properties that are 100% self-catered and self-contained.
This can include homestays when their facilities meet our criteria for a holiday rental stay.
As not all homestays meet this criteria, you won’t find all of the homestays on Booking.com, listed on Villas.com as well. The main difference between booking a homestay on Booking.com versus Villas.com is related to kitchen facilities.
Booking a vacation rental with Villas.com will guarantee customers have access to a kitchen or kitchenette allowing them to self-cater, whereas a homestay offered on Booking.com could possibly mean not having access to these facilities."
UPDATE 15 July: Booking.com responds to this Tnooz article with details on how to list an Airbnb-style homestay on Booking.com
EARLIER:
Google quietly adds instant booking for hotels, copying TripAdvisor
Airbnb quietly starts a pilot for listings exclusively for business travellers