Inside Airbnb, a data visualization tool released this week activist Murray Cox, scrapes Airbnb's public data for New York City users.
The site's analysis of Airbnb's data casts doubt on the company's core claim, namely, that its core users are renting out their condominiums or spare rooms occasionally to make a few extra bucks.
Inside Airbnb instead estimates that nearly 16,000 entire apartments have been rented an average of 247 days a year.
About half the apartments listed don't have the owners accompanying the guests during the stay, according to the interactive map of listings.
If true, that's troublesome, because it was only months ago that New York state Attorney General Eric Schneiderman argued that many of Airbnb's users are breaking rental and zoning laws.
Airbnb says the company doesn't comment on scrapes of its information because such scrapes use information inaccurately.
Scraped data doesn't reveal how often the properties are actually rented. The site uses the frequency of reviews as a proxy.
Cox claims the data was scraped from 27,392 New York City listings posted in the first three days of January.
The tool has been promoted by the ShareBetter coalition, made up of tenant groups, advocates for affordable housing, and city officials. The group says the data shows that three out of four listings are "potentially illegal."
In other news, Credit Suisse analysts argue that hotel room rates in some districts in New York are 5% below where their mathematical models say they should be. They say hotels face competition from Airbnb listings.
Hotels: take your heads out of the sand and get over the Airbnb threat
How to kill Airbnb at its own game