Google remains a powerful dashboard for the Internet's vast library of information, said Lee Rainie, director of the Pew Research Center's Internet & American Life Project. But now that two-thirds of online adults are creating and sharing their own content, new navigational tools are needed.

Facebook's "ascendance highlights the degree to which the online environment has become participatory and social," Rainie said. "Facebook has radically intensified the communication and sharing features that have always been part of online life."

Read More