Big Fuel, a New York-based marketing and communications agency, will open a Detroit office to handle social media campaigns for General Motors (GM).The expansion will allow Big Fuel to work with GM on a day-to-day basis, according to Seth Berk, VP of business development at Big Fuel. The two companies will collaborate on social media marketing campaigns structured around each individual GM brand line. The campaigns are expected to be rolled out throughout Q1 of 2011.