In a city known for its boom-and-bust real estate cycles, this one may go down as the shortest of the short booms. It lasted about three months. New data shows that Amazon’s announcement that it was going to bring a second headquarters to Long Island City, Queens, triggered a gold rush of condo buying in the neighborhood, according to listing information portal Online Residential.

Between Nov. 13 and Feb. 13 — the time between Amazon announcing and canceling its plans for a 25,000-job headquarters in the city — there were 157 contracts signed on homes in Long Island City and Astoria. That marked a 99% increase on contracts signed in the two months leading up to the big announcement on Nov. 12 last year, the New York Post reports, citing building and listing information portal Online Residential.

As agents’ frustration with listings portals continue, On-Line Residential has launched a consumer-facing marketplace for residential listings. The website, dubbed Linecity, promises to give agents full control over their listings.

Part of the problem is that brokerages, which all feed into the RLS, have different listing platforms that use varying technology. Many are also reliant on vendors like On-Line Residential, RealPlus and Perchwell to send listings data to the RLS.

“The past decade has not been kind to the traditional rental agent. The use of the internet by landlords and consumers has changed the industry considerably. Should this legislation pass and fees are capped, this sector of the industry will be crippled beyond repair,” said Jonathan Greenspan, president of On-Line Residential (OLR), an online multiple listing service for brokers.

According to data from the listings portal On-Line Residential, 79 contracts were signed in LIC and Astoria between Sept. 13 and Nov. 12 of last year — before the deal with Amazon was announced, the New York Post reported late last month. That number shot up 98 percent to 157 between Nov. 13 and Feb. 13, during the period when Amazon was on its way to LIC.

The change of heart comes after a series of petitions and campaigns have been launched by organizations representing and servicing rentals agents, including On-Line Residential which has garnered more than 2,100 signatures, and brokerage Level Group, which has 300 signatures. The Real Estate Board of New York has also coordinated a series of meetings between brokers and their home and work districts’ council members.

Town already lost many of its big-name brokers over the past few months, but several remain — including Steve Gold, a co-star on Bravo’s “Million Dollar Listing: New York,” and Tribeca specialist Danny Davis. Dana Power has several of Town’s biggest listings, including a penthouse at 129 Lafayette that’s asking $16.95 million. And Gold currently has $66 million in listings and $20.8 million in signed contracts, according to On-Line Residential. Several listings are at the Circa, Artimus’ condo project at 285 West 110th Street.

From the March issue: Back-end listings systems for residential firms has long been the domain of two firms: RealPlus and On-Line Residential. But with a slew of new venture-backed competitors such as Perchwell and Nestio breaking onto the scene, the landscape is shifting.

What we found was that as a group, the top 20 agents were marketing a total of $6.7 billion worth of properties as of April 30, the one-day snapshot when we culled listings from On-Line Residential. That’s essentially flat compared with the $6.6 billion worth of properties marketed by the top 20 agents last year.

The m-word has been lobbed at Streeteasy before. The Zillow-owned company has built up such clout in New York’s Online Residential listing market that brokers who balk at the new charges, or at its new Premier Agent feature that auctions off the right to advertise next to a listing, have no feasible alternative. Sure, there’s Realtor.com or Craigslist, and they all benefit from the tension StreetEasy’s new fees create. But none of those platforms offer anything close to StreetEasy’s reach in New York. Jonathan Greenspan, president of On-Line Residential, said at TRD’s Big Data + Real Estate Forum in March that the company was a virtual monopoly.

Of 114 properties on the Upper East Side that were asking $15 million or more on June 13, sellers were offering 2 percent commissions to the buyer’s agent on 15 percent of listings and 2.5 percent on 41 percent of listings, according to an analysis by TRD of properties listed on On-Line Residential.

The Real Deal’s annual ranking of top companies — which is based on agent count and is tallied from a one-day snapshot of data from On-Line Residential on March 27 — shows that many of Manhattan’s largest residential firms grew in size in 2016. The ranking also saw the cumulative dollar value of sales listings climb, as both median and average sale prices ticked higher.

TRD’s ranking — which is based on listings culled from the listings portal On-Line Residential on May 31 — includes exclusives and properties that went into contract on or after January 1. Needless to say, the ranking is not designed to capture every facet of an agent’s business — closed deals and buy-side transactions, for example, are not part of this tally. Instead it is meant to be an across-the-board snapshot of who is marketing what.

Dolly Lenz’s eponymous firm again dominated this year’s ranking of boutique brokerages, according to TRD’s data, which was pulled from listings portal On-Line Residential on March 27. Firms with between two and 49 agents qualified.

A Manhattan townhouse where Eleanor Roosevelt once lived is listing for $18 million. On-Line Residential

Moderated by TRD’s Katherine Clarke, panelists also included Doug Curry, CEO of Xceligent; Jonathan Greenspan, president of On-Line Residential; Richard Persichetti, regional director at Cushman & Wakefield; and Nick Romito, CEO of VTS.

The second panel, moderated by TRD‘s Katherine Clarke, brought together Doug Curry, CEO of Xceligent; Jonathan Greenspan, President of On-Line Residential; Richard Persichetti, Regional Director, Cushman & Wakefield; Nick Romito, CEO of VTS; and Harley Courts, CEO of Nooklyn. The topic was the increasing value of big data, the methods of collecting it and the importance of protecting it.