To earn extra money while managing the Phelps office, Domb earned a real estate license at
Temple University. As the real estate business became more profitable, he quit the security business job and sold real estate full time, opening his own office in 1983. Domb specialized in real estate near Philadelphia's
Rittenhouse Square and soon became well-known among property buyers and sellers in that neighborhood. He was elected president of the Greater Philadelphia Association of Realtors (GPAR) in 1990, the youngest president that organization had ever elected. After success in real estate sales, Domb expanded into real estate development in 1999, and worked with restaurateur
Stephen Starr to develop restaurants in Philadelphia. Domb was again elected president of the GPAR in 2013, by which time he had acquired the nickname "Philly Condo King." In his second term as GPAR president, he worked with Mayor
Michael Nutter and the city government on ideas to collect delinquent property taxes and attract new residents to the city. He also worked with
City Council President
Darrell L. Clarke to determine the market value and ultimate disposition of some of the city's inactive school buildings. Even after entering politics, Domb remained active in the real estate business, purchasing a 19-story office building in April 2016. ==Political career==