Airbnb may have built its reputation as the go-to site for travelers seeking hotel alternatives.

But now small hotels are using the lodging site to fill vacancies--and they say with good reason.

According to Fast Company, boutique hotel managers say they are now leveraging Airbnb, which has long been seen as a threat to the traditional hotel industry, in a similar way to Expedia and Priceline, which “typically charge hotels a 10 percent to 25 percent fee per reservation.”

Airbnb’s fee of just 3 percent makes it a much more attractive option for smaller hoteliers.

"Any hotel that needs to fill rooms, I don’t understand why they wouldn’t need to use it as one of their marketing arms,” Stephan Westman, a hotel industry consultant who has listed hotel rooms on Airbnb, told Fast Company.

An example of one such hotel listing rooms on Airbnb is The Box House Hotel located in the trendy Brooklyn, N.Y. neighborhood Greenpoint. It offers just nine apartment-style suites, at least five of which are listed on Airbnb. Manhattan’s The Riff—a former hostel recently converted into a hotel— and The Union Hotel in Gowanus, Brooklyn are also offering up rooms on the short-term rental site.

Hotels in Chicago, Denver and Los Angeles have also expanded their offerings to be included on Airbnb.

Wrede Petersmeyer, Airbnb's New York City manager, told Fast Company that the company permits hotels and hostels to list on its site as long as they are portrayed accurately.

But even some hotel managers who use the site say it’s bad for the industry.

"There are many other ways it could be an actual opportunity instead of taking people out of our business and putting them into an apartment business,” Daniela Benhamou, a manager at New York Loft Hostel, told fast Company. “It’s definitely not a good thing for the hostel industry."

Airbnb currently has over 2 million listings available. Though the company has not released data on how many hotels actually list on its site, information released earlier this month showed 3,500 New York City listings belonged to hosts with three or more entire home listings on the platform—which critics argue allow individuals to skirt hotel licensing laws and also limit the number of available housing units in already tight real estate markets.

Still, booking sites like Priceline—which owns Booking.com and Kayak—know the threat from Airbnb is real. It listed the website as a competitor in its SEC filings.

But Expedia, which recently announced plans to acquire Airbnb competitor Homeaway for $3.9 billion, recognizes that smaller hotel brands can gain greater visibility by using peer-to-peer rental sites—even if the homeowners are the competition.

At a conference earlier this month, Expedia CEO Mark Okerstrom acknowledged Airbnb could become a credible threat but “at the same time, we look at what Airbnb is doing, and we look at that as a potentially attractive opportunity for us."