Vanguard and its clients have been studying failure demand since we first originated the concept.
It is common to find failure demand running at 30 to 60% of all demand in financial services; it can be as high as 70 to 90% in telecommunications, police and local authorities.
The lowest ever found was 15% in a financial services firm that was set up to provide service over the phone (so, good but no cigar).
While failure demand is an easy concept to understand, it is also easy to misunderstand its causes.