"Real estate has a lot of room to run before the Zillow brand has anywhere near the brand recognition of Expedia," Barton says. Online real estate advertising dominated real estate advertising in the U.S. in 2014 with a projected $10.69 billion in spend, or about 78.5 percent of the market, according to Borrell Associates' "2015 Outlook, Real Estate Advertising." Zillow and Trulia combined had about a 7 percent share of the U.S. digital advertising market for real estate.