The portal wars are heating up! And CoStar is more than ready for it. 

While no one questions Zillow’s rank as the number one real estate portal, when CoStar CEO Andy Florance put in the number two spot last October, based on reliable traffic data, rivals in the portal space took issue with that and used secondary sources like Comscore to prove him wrong. 

Competition among the four major portals is likely to intensify, with CoStar and both aiming for the top. 

On this week’s episode of The Real Word, hosts Byron Lazine and Nicole White reviewed comments made by four real estate CEOs at Inman Connect New York (ICNY), starting with a quote by CoStar CEO Andy Florance defending his company’s growth stats and their source. 

We can’t lie. If I lie about a number in public company reporting, I go to jail four times as long as you’d go to jail for shooting someone in the head in the street. Public companies don’t make these things up.

Andy Florance

CoStar CEO

Read on for some of the highlights. 

Comments from Andy Florance at Inman Connect New York

Back in October (2023), CoStar announced had surpassed as the second largest residential real estate portal. According to CoStar Group, monthly unique visitors skyrocketed from 46.3 million in August to 100 million in September—an increase of 117%. 

CoStar’s rivals, including, were none too pleased by the announcement and presented alternative traffic data from Comscore, Semrush, and SimilarWeb to try and disprove CoStar’s growth stats. 

Unfortunately for them, as CoStar CEO Andy Florance pointed out, that 117% jump was based on data from Google Analytics, widely-regarded as the gold standard and relied upon by Zillow,, and Redfin for their own traffic data. 

I always find Andy Florance refreshing… He leans into competition. He calls out competitors consistently—does this over and over and over again. I like that… If residential real estate didn’t have the pleasure of Andy Florance entering the space, it’d be the most boring industry in the world…

Byron Lazine

That wasn’t the only reason Florance called out his competitors. 

At Inman Connect New York (ICNY), Florance threw some shade at “Ziltorfin” (Zillow, and Redfin) for engaging in bait-and-switch tactics that serve corporate bottom lines at the expense of buyers and agents. 

That’s ultimately why CoStar leadership is confident in their ability to topple the “final giant,” Zillow, from its position as the number one ranked portal by web traffic. 

[People] conflate high traffic with a positive consumer experience, but they’re two separate things. Traffic is traffic, positive consumer experience is positive consumer experience.

Andy Florance

CoStar CEO

According to a Real Estate News, came in fourth

A Real Estate News article uses the same Comscore data presented by CoStar’s competitors to show that was actually in fourth place last October, not second. 

Comscore traffic data shows Zillow with double the number of visitors compared to second–place portal, Meanwhile, lags just behind Redfin. 


The question remains how Comscore data diverges so significantly from the traffic data provided by Google Analytics, which, as Florance pointed out at ICNY, all four portals use. 

According to Comscore, and were neck-and-neck last September, with 47.7 million unique visitors for the former and 51 million for the latter. Comscore data for September, though, shows losing ground and falling to fourth place in October.

In November, speaking of the competition, president David Mele told Real Estate News, “They all buy traffic” adding that, ultimately, consumers will decide which portals deliver enough value to cement their position in the industry. CEO loves the competition; Compass CEO supports CoStar

Also speaking at Inman Connect New York, CEO Damian Eales expressed enthusiasm for the rivalry between his company and CoStar. With both aiming for the number one spot, competition is not only expected but invigorating. 

Meanwhile, Compass CEO Robert Reffkin voiced support for CoStar and its CEO. Both know what it’s like to be underestimated by big names in the industry, and both have exceeded expectations. 

Time will tell just how quickly the naysayers will eat their words. 

Watch the full breakdown on The Real Word