Realtor.com sent out an email boasting that it had more listings than Zillow.com “in many major U.S. cities.” Only three “major” cities were shown — San Diego, Austin, and Denver — and the comparison was old (data were from mid-October 2016). That’s a very small sample of a narrow snapshot.
A closer look using a more objective method yields very different results.
Coming up with a random sample of U.S. cities is not simple. We looked for single-family homes in every U.S. city named “Springfield.” We found 27 such cities, ignoring variants (e.g., “West Springfield”).
The table below shows the results. Realtor.com had more listings in 8 of 27 cities(30%) and 8 of 21 cities without ties or missing data (38%). Zillow.com had more listings in 48% and 62%, respectively.
Zillow.com is not the only competitor to Realtor.com. Another is Trulia.com. When the same analysis is done including Trulia.com, Trulia.com is the clear winner. It has more listings than both Realtor.com and Zillow.com in 13 of 27 (48%) cities named Springfield, with Realtor.com and Zillow.com having more listings in 5 (19%) and 3 (11%), respectively. When cities with ties and missing data are removed, Trulia.com has the most listings in 13 of 21 cities (62%).
Of course, any exercise like this has many limitations that, if corrected, could change the results. For example, the two systems may use different geographic boundaries. Realtor.com didn’t cite any limitations in its comparisons and refused to disclose a copy of its analysis. More importantly, comparisons across cities named Springfield are not more useful to consumers than comparisons for San Diego, Austin and Denver. The analysis above is transparent and can be reproduced by anyone. Analyses that lack transparency, whether published by government or the private sector, deserve to be ignored.
Home shoppers using online search tools should use all of them, keeping in mind that all listings won’t be reported on all services.