You’ve probably seen the news that Zillow is going to be the exclusive provider of listings to Yahoo! Real Estate, as well as be the exclusive seller of ads to agents and brokers for inventory on YRE. What is the significance of the number 2 and 3 sites in the real estate joining forces? The fact that YRE!’s listing will be powered by Zillow is a nice win meaning that agents and brokers will have one less place to syndicate to, but the real news here is the creation of the Zillow-YRE Ad Network. In short, it means more money for Zillow and Yahoo! Real Estate and less money for Realtor.com.

Those who have done online ad sales, and those who have been pitched by online ad salesmen, know it’s powerful tool to be able to say “We’re the largest site in [category X]” when speaking to a potential advertiser or partner. The Zillow/YRE combo now completely dwarfs the size of Realtor.com in overall audience. Realtor.com is rumored to have somewhere in the range of 12 million uniques, while Zillow was at 10.7 last month and, without knowing anything other than that they are the number 2 site, I’m guessing Yahoo Real Estate was around 10 million as well. That means the Zillow Ad Network now includes 20+ million uniques a month. That fact alone means that more money is going to shift towards Z/YRE and away from Realtor.com.

The CNNMoney deal was a nice win for Trulia, but this Yahoo! deal completely blows that out of the water in my opinion. CNNMoney is certainly a massive site, but Traffic on CNNMoney is not really specifically looking for real estate — traffic on Yahoo! Real Estate certainly is.

As for Realtor.com, I hope they have a few massive innovations or strategic deals up their sleeve or else it’s going to be a rocky road ahead for their sales team. I’m guessing there will be a fair amount of chatter about this deal at Inman next week

PS: I’m obviously biased on this issue since I worked at Zillow for 4 1/2 years and as a stockholder am certainly thrilled this deal (which was in the works prior to me leaving in January) got completed. But now that I don’t work for Zillow I can actually comment on big announcements like this 🙂