Want a Home? Get Your Phone: Zillow CEO

More Zillow home listings are now viewed on mobile phones than over the Internet, and CEO Spencer Rascoff tells CNBC he couldn't be more pleased.

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This is one case when online "advertising is content, not distraction," he told Squawk on the Streeton Thursday, a day after the company reported first-quarter earnings that exceeded analyst expectations. "If we could get 80 percent on mobile, that would be fantastic."

Zillow connects those seeking homes with real estate agents. The site has property information on 100 million homes, Rascoff said, but the market will be expanding because of Zillow's purchase of RentJuice, which makes software that allows brokers and landlords to collaborate and share listings. The $40 million acquisition of the San Francisco-based company is expected to close in the second quarter.

"Rentalsis a huge market," Rascoff said. "Seventy percent of movers are renters. So you can't be a significant real estate company without rentals."

Five million people use Zillow every month for rentals, he said, but the RentJuice acquisition "puts us into the professional side."

Zillow has "less than 1 percent of what real estate agents spent on advertising. So real estate agents spend 99 percent of their ad budgets elsewhere, even though we’re the largest real estate website. That’s the market we’re chasing."