The Point of Adoption (PoA) is not to be confused with the critical mass ‘inflection point’ on the S-curve [67,68]; or with the ‘tipping pint’, the critical threshold introduced by Gladwell [22].

[22] M. Gladwell, The Tipping Point: How Little Things Can Make a Big Difference, Abacus,
London, 2001.

[67] E.M. Rogers, Diffusion of Innovations, Free Press, New York, 1995.
[68] E.M. Rogers, U.E. Medina, M.A. Rivera, C.J.Wiley, Complex adaptive systems and the
diffusion of innovations, Innov. J. Public Sect. Innov. J. 10 (3) (2005) 1–26.