Best known for years as the pitchman of Rock Financial before a falling-out with his boss, Dan Gilbert, David Hall has launched a mortgage company in Birmingham called Hall Financial. During his 12 years at Rock Financial, Quicken’s mortgage lending arm in Michigan, Hall, 39, appeared in numerous TV and radio commercials for the company. The superstar salesman rose to become Rock’s senior vice president and chief marketing officer. But in late 2007, Hall abruptly left Rock and started his own marketing and consulting business. In March 2009, Hall and Gilbert were in an alleged shoving match at Birmingham’s Townsend Hotel. Police closed the case without bringing any charges. Hall said he has not suffered any repercussions from the incident. When his noncompete agreement with Quicken ended late last year, Hall decided to form his own company. Though Hall acknowledged that now is not the best time to start a mortgage firm, he said, “It’s a good time for me to get back into the business I really like.”