Stefan Doerrfeld won’t hold an open house on the weekend. “Buyers have access to listing information 24/7,” says Doerrfeld. “Why would they wait until Sunday to see a house?” Doerrfeld hosts virtual open houses; online, each listing has a detailed tour, produced by a professional videographer. And he remains on call—always—for private showings. He launched his trademarked brand, “The 24/7 Agent,” in July 2013 and says it helped him achieve a 48 percent increase in sales last year compared with 2012. Determined not to lose a potential customer, day or night, he even invested in solar-powered LED lighting for his yard signs to make sure the “Open 24/7” signage could be seen, well, 24/7.