· 2014. 5. 15. · 2007, Kindle 2 in 2009, and Barnes & Noble's Nook in 2009, sharply...
3
· 2014. 5. 15. · 2007, Kindle 2 in 2009, and Barnes & Noble's Nook in 2009, sharply increased consumer demand for electronic content. Prior to Apple's entry into the e- book market