Airbnb has proven to be a serious side hustle for Louisvillians.

The city ranked No. 2, just after Chicago, among the 14 largest sharing cities in the Midwest for number of hosts, a recent study by the company found.

“The rapid growth of Midwest home sharing is turning historically great communities into truly global destinations,” the study said.

That line echoes arguments common to both sides of an ongoing debate in Louisville over the home sharing service. For some, it’s going to destroy the fabric of historic — and historically livable — neighborhoods. For others, it’s driving up their value.

The Airbnb report compiled data from July 2015 to June 2016. During that period, roughly 1,200 Louisvillians have hosted guests and typically earned just about $4,000. The company reports more than 32,000 guests staying at Airbnb places in Louisville. Chicago had 5,000 hosts and just more than 315,000 inbound guests.

Since Aug. 1, when a new law took effect, Louisville has required hosts to register their home rentals. As of Aug. 29, only 22 people had done so.

The Metro Council approved the so-called Airbnb ordinance to regulate time limits of renters, safety and occupancy limits. It came about in response to complaints that the short-term rentals were changing neighborhood dynamics, as well as stiff complaints that the longtime competitor to hotels was being permitted by city government to duck the rules because hosts didn’t have to pay occupancy taxes.

Since the onset of the sharing economy, startups have sprouted that can help users find a parking space to those that guide self-acclaimed chefs in turning their kitchens into restaurants.

Cities across the country have struggled to deal with competition against traditional models. For Airbnb, the debate has been over how to balance the safety of renters and quality-of-life issues for neighbors alongside the booming new economic model. It’s a debate common in the sharing economy: The ride-sharing company Uber has gone through similar battles with cities and the taxi industry.

Louisville hosts have 90 days from Aug. 1 to register their properties. Joe Reverman, assistant director of Louisville Metro Planning and Design Services, said violators would be notified to comply with the ordinance. There is no plan to search for unregistered rentals on Airbnb and similar sites, he said.

“Our enforcement is on a complaint basis,” Reverman said. “And just advertising your site on Airbnb is not a violation. You would have to actually have to host the Airbnb.”

Complaints would be received through Metro’s 311 phone number.

Those who want to host on home sharing sites have to register in-person or by mail. Reverman said the option to register online would be coming “soon.”

“It’s pretty much any day now,” he said. “We’ve had daily conversations with I.T. trying to get that up and running.”

Cleveland, Indianapolis and Minneapolis followed Louisville, respectively, rounding out the top five cities for number of hosts. Milwaukee and St. Paul were last on the list, with 200 hosts over the time studied. Typical earnings for a host in those cities was $5,000 or more.