For the last few months, the home-sharing company has been testing a program that lets its hosts enlist the help of another to respond to messages from guests, greet them when they arrive, help if they have any issues, and any of the other hosting duties, as Fortune previously reported.

Now, Airbnb has extended the program beyond its initial four test cities to include Miami, Dublin, Seattle, and Austin, and will add even more markets next week.

The idea was born out of something hosts were already doing on their own, so the company decided to build a feature to let them do it more easily, Airbnb director of product Donna Boyer tells Fortune.

This strategy also offers the potential for more transparency. When booking a stay, guests will clearly see who owns the home where they’ll be staying as well as the host they’ll interact with during their stay. This may not have always been clear in the past when hosts didn’t have the ability to add a co-host to their listing’s profile page.

As for hosts and co-hosts, this new program also makes things easier to manage. Airbnb has built a payment feature that handles splitting the earnings between the hosts in whatever proportion they choose. Most co-hosts received between 10% and 20% of the earnings during Airbnb’s testing period, according to Boyer, though there’s not a required rate. Hosts can also send ad-hoc payments to co-hosts in the event of an expense, such as purchasing additional toilet paper or groceries, or for a home cleaning before the next guest’s arrival.

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There are two ways for hosts to add a co-host: by inviting a specific person they already know (such as a trusted friend or neighbor), or by searching for nearby qualified hosts who opt into serving as a co-host. In the second case, Airbnb matches the hosts based on location, availability, and so on. While only “Superhosts” (hosts who meet certain criteria including high ratings and frequent hosting) were allowed to function as co-hosts during the initial testing phase, Airbnb says it’s expanding to include other hosts who also have great ratings but don’t necessarily meet the frequency requirements to be a Superhost.

“As a host, you’re also able to help someone who is not currently sharing their home to start hosting,” says Boyer.

To date, more than 46,000 hosts have added a co-host to their listing, according to the company, a signal that it’s a popular feature. Airbnb’s initially tested this program in Tokyo, Toronto, Chicago, and Washington, D.C.

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Airbnb also says it’s committed to not let professional listing management companies take advantage of this new program, which it says is intended for individuals. The home-sharing company is often criticized for enabling greedy landlords to turn their buildings into illegal hotels, and this co-hosting program could make that activity even easier.

That said, things could change as the program grows. Last year, Airbnb made special software for vacation rental property managers available in select markets, demonstrating a willingness to allow some commercial operations on its service.

Airbnb’s co-hosting program is only part of the company’s efforts to grow its business beyond its original home-sharing model. On Thursday, during an annual conference in Los Angeles, the company is expected to unveil a long-rumored way for guests to book activities through Airbnb, not just lodging. Airbnb has been experimenting with an activities service for the past two years, quietly testing this service over the last several months in select cities, according to media reports and a source who spoke to Fortune.