Zillow is the most popular real estate website in the United States. The company has transformed the way people buy, sell, and rent homes, or at least dream about that kind of thing. >> We are one of the first apps on the iPhone, and that really created the category.>> Realtor. com, Zillow, some of the other aggregation sites that are out there provided an experience for consumers that wasn't there before. Zillow, what they have an advantage on is just the scale of traffic that they've got is quite substant ...