Five waves of digital textbooks in the US – 2000 – 2014

Here’s an article from Xplana with the above title. It discusses:

Experimentation (2000-2003)

Early markets (2004-2006)

Proliferation and integration (2007-2008)

Profitability and social learning (2009-2011)

Standards and disaggregated distribution (2012-2014)