One-third of cell phone owners access news on their handsets, according to new data from the Pew Research Center, and 37 percent of Internet users have contributed to the creation of news, commented about it or disseminated it via postings on social media sites. Interestingly, the Pew’s figures were released the same day this story was published detailing the Associated Press’s plans to attempt to use a paid subscription model for its content on mobile devices. Monetizing digital content has never been easy for new outlets, of course, and Pew’s findings highlight one important reason why: It’s difficult to get people to virally distribute your stuff if you’re charging a premium for it. That’s a challenge AP and its counterparts will have to address as they try to make money in moile.