An excerpt from the press release.
Study noted by the 'In the News' email newsletter on digital copyright from the Center For Intellectual Property at the University of Maryland University College.
Creative Commons noncommercial licenses preclude use of a work “in any manner that is primarily intended for or directed toward commercial advantage or private monetary compensation.” The majority of respondents (87% of creators, 85% of users) replied that the definition was “essentially the same as” (43% of creators, 42% of users) or “different from but still compatible with” (44% of creators, 43% of users) theirs. Only 7% of creators and 11% of users replied that the term was “different from and incompatible with” their definition.
Study was discussed in Plagiarism Today blog from Johnathan Bailey.