Almost two-thirds of New York City listings on Airbnb are illegal, according to an in-depth report released today by the travel news site and market research firm Skift, a perennial Airbnb ankle-biter. That's worse than Skift's previous, less technical estimate, which said roughly 50 percent of listings violate the law.

The New York attorney general subpoenaed Airbnb for host data back in October. The company refused to hand it over, saying the request was too burdensome, so Skift decided to do it for them. The blog commissioned Connotate, a data extraction and monitoring firm, to comb through the site's listings over the course of a month.

The result basically confirms what most New Yorkers with experience with Airbnb would have guessed. Most users would rather rent an entire home or apartment — the condition that is illegal under New York City law — while some users will rent a private room and only 2 percent are interested in a shared room.

Listings for an entire home or apartment are illegal in New York City

When hitting back at cities that want to regulate it, Airbnb likes to emphasize two things: its economic impact, and the number of hosts who are just renting out their own space in order to make an honest extra buck (87 percent in New York City, Airbnb says). The Skift numbers don't contradict Airbnb's official line, but they do reveal some insights the company would rather ignore.

For example, while it's true that a majority of hosts on the site only list one property, about 30 percent of New York City listings come from the minority of hosts who list more than one property. That indicates that a good chunk of Airbnb's revenue comes from hosts who are managing more than one property, which indicates a certain level of professionalism. These multi-property hosts are managing listings for foreign investors, landlords, or friends, Skift concludes, which is not the type of user Airbnb likes to promote.

Airbnb, which investors say is worth around $2.5 billion, is due for a court battle with New York in March. Like Uber and other startups that clash with regulators, Airbnb believes that the demand for the service justifies a change in the law to accommodate it.

30 percent of listings come from hosts with more than one property

Airbnb has not responded directly to the Skift report, but today the company released its own numbers highlighting its economic impact by borough in New York City. It estimates a $528 million boost to Manhattan alone. "In every borough in New York, hosts are welcoming people from all over the world to share their rooms, homes, and apartments," the company says. "Residents are using the money they earn to pay their bills, afford their rents or mortgages, and pursue their dreams."