An election sign in San Francisco's Chinatown in late October supporting a ballot initiative that would have more strictly regulated Airbnb. (AP Photo/Eric Risberg)

Airbnb, fresh off waging — and winning — a political brawl in San Francisco last week, struck a more conciliatory tone on Wednesday with the cities where its fast-growing home-sharing service has blurred the lines between the hotel and housing markets. The company released what it called a "community compact," pledging to ensure that its users pay their "fair share" of local hotel taxes and offering for the first time to publish local reports on the scale and impact of its business.

The offers come with a caveat; they're extended only to "those places that respect the right of people to share their home." If cities aren't hostile to Airbnb, in other words, Airbnb promises to be more transparent and cooperative.

The most notable concession in the compact, though, is not about these two big-ticket items, taxes and data (Airbnb is already collecting taxes now in several cities, and it has been forced to turn over data in New York). In some markets, Airbnb says, it will start requiring hosts to agree to a policy of listing only properties that are permanent homes. In explaining this policy, the company pledged on its blog:

In cities that have not established rules for home sharing, and where housing prices and availability are a critical issue, we will work with our community to help prevent short-term rentals from impacting the availability and cost of permanent housing for city residents.

That concession is striking because it implicitly acknowledges that Airbnb may, in fact, be impacting the housing supply, a criticism the company has largely dismissed until now.

The distinction around permanent homes has become central to the political fight over whether Airbnb is helping or hurting affordable housing. Airbnb argues that the income hosts earn through the site helps subsidize their own high housing costs (the data it plans to release will include the number of hosts who supposedly manage to avoid eviction or foreclosure thanks to their Airbnb income).

But in expensive cities like New York, San Francisco and Los Angeles, critics have argued that property owners aren't simply renting out their homes for extra income, but converting homes into full-time mini-hotels, permanently removing properties from the rental supply. To combat the practice, San Francisco's new regulations allow only residents to list their permanent homes for short-term rentals.

Airbnb was vague about the details of how this new policy will work — whether it will actively try to ferret out accounts listing multiple properties, or how it will crack down on hosts caught doing that. Airbnb also didn't specify the cities where this policy will apply. But the company said that it "strongly oppose[s] large-scale speculators who turn dozens of apartments into illegal hotel rooms." And a spokesman said the company plans to release data to prove that it's "walking the walk."

The data that it's offering to release, in annual reports, include anonymized information on the income earned by typical hosts, the geographic distribution of listings, and the share of hosts renting their permanent homes. Data on the company's impact so far has been gleaned mostly by media outlets and housing activists scraping public listings for clues as to whether the company is contributing to a shortage of affordable housing.

Currently, Airbnb says, its own surveys suggest that 80 percent of hosts in the U.S. list their permanent home on the site. In San Francisco and New York, it says the figure is 90 percent.

"We are proud of almost all of the activity that happens on our platform every day,"Airbnb CEO Brian Chesky wrote in announcing the compact. "But it’s become clear that we need to clarify what we will and will not tolerate in our community."

That was uncharacteristically stern language for a company that has over the last five years built a careful brand around the feel-good ideas of "belonging" and "sharing."