Prepare yourself for a heavy new dose of Brad Bellflower and the "apartmenternet." CoStar Group Inc. (NASDAQ: CSGP) plans to launch a $250 million ad campaign for Apartments.com with actor Jeff Goldblum reprising his role as Bellflower, in a bid to drive more traffic to its multifamily rental website. The District-based commercial real estate technology data firm is upping its marketing spend on the ad campaign, developed by California-based ad agency RPA, by about $100 million. That means expect...