The Duluth News Tribune reports the St. Paul-based company wants to help libraries continue to expand their collection of digital material with the "Cloud Library" system. 3M and libraries have worked together for more than 40 years, but other e-book services are already up and running. 3M's Tom Mercer says the company has "an opportunity to innovate and create the best platform for libraries." He also says in about three years, a third of all reading material sold in the U.S. will be digital.