This term is used to describe how long a particular market will patiently wait for something promised to them. These days it is common to "
pre-announce" something, and if enough time passes between anouncement and release, the market will reflect a loss of user interest.
For example, Netscape 6 has now, to all interested observers, pretty much broken their ample Market Elasticity due to repeatedly delayed releases. This also occurs with games frequently (Ultima X comes to mind).