"The percent of U.S. adults with an e-book reader doubled from 6% to 12% between November 2010 and May 2011. Hispanic adults, adults younger than age 65, college graduates and those living in households with incomes of at least $75,000 are most likely to own e-book readers. Parents are also more likely than non-parents to own these devices." -- Overview, E-Reader Ownership, 6/27/11
It would be interesting to learn more, such as those who use E-Readers via their local library (academic or public), or what percentage of E-Readers purchased outside of those for personal use were utilized in classrooms or libraries.