Ad agency Twitter feeds are, as a rule, about as interesting as a couple at Home Depot debating which paint chip would best match their duvet. One consistent exception has been R/GA, which serves up fun links and clever insights with a biting wit. The man behind the feed is Chapin Clark, evp and copywriting chief based in the agency's New York headquarters. We spoke with Clark about how he keeps @RGA's tweets interesting and whether he offends any peers or potential clients in the process. He also shares some advice for how agencies and brands can turn their Twitter feeds into something worth reading. Check out the Q&A below.