Editor’s note: Inman News, in citing a Zillow corporate blog announcement at Zillow.com, had originally reported that ComScore’s data showed that Zillow had pulled ahead of Realtor.com in monthly visitors, though according to this article Zillow had based its report on incompatible statistics.
Zillow.com jumped the gun in claiming to have surpassed Realtor.com in November as the most visited real estate Web site on the Internet, according to the purported source of the claim, Web metrics provider comScore Inc.
Zillow’s claim that it had surpassed Realtor.com was based on a non-public report issued by comScore, which recently began using a new methodology for tallying visits to Zillow.
ComScore had not yet implemented the new methodology for other top real estate Web sites in November, according to a copy of the report Zillow provided to Inman News.
In a recent policy bulletin, comScore advised clients that in comparing themselves to their competitors, companies should use a separate set of reports employing only the previous "panel based" methodology across all sites. Otherwise, sites still making the switch to the new "hybrid methodology" would be "unfairly penalized in ranking during the transition."
The bulletin warned that "changes in rank that are a result of mixed methodology comparisons are not allowed."
In post on the company blog Thursday, Amy Bohutinsky, Zillow’s vice president of communications, cited a comScore report that showed Zillow.com tallying 5.231 million "unique visitors" during November, compared to Realtor.com’s 5.223 million.
Inman News published a story repeating the claim Thursday evening, and retracted the story Friday morning after Realtor.com operator Move Inc. questioned its accuracy.
A comScore spokeswoman said Friday that an "apples to apples" comparison using the "panel-based" methodology to evaluate traffic across all top real estate sites showed Zillow with 3.013 million unique visitors in November, behind Realtor.com, Yahoo Real Estate, and AOL Real Estate.
"Zillow.com is now being measured with our hybrid methodology which caused its figures to grow largely from (October to November), such that a significant portion of its growth was attributable to this change and not necessarily due to organic growth at the site," said comScore spokeswoman Sarah Radwanick in an e-mail. …CONTINUED