Each Office Is Independently Owned and Operated. ©1999/2008 CENTURY 21 Real Estate Corporation. © and SM - trademark and servicemark of CENTURY 21 Real Estate Corporation. CENTURY 21 Communities® is a service mark of Century 21 Real Estate Corporation Millward Brown Disclaimer: 1999 Advertising Tracking Study. This survey included 400 telephone interviews with a national random sample of adults who have bought or sold a home within the past two years or plan to purchase or sell a home with the next two years. The survey was conducted from February 11-14, 1999 and June 6-9, 1999 by Millward Brown, a leading research agency. Results from this survey have a 95% confidence interval of +/- 4.9%.