Self - described ` ` Undisputed Master of Motivation '' was known for his seminars . ( CNN ) -- He wrote more than two dozen books on salesmanship and marketing . ` ` Failure is a failure , not a dead - end , '' is one of many famous stock quotes .
Self - described ` ` Undisputed Master of Motivation '' was known for his seminars . He wrote more than two dozen books on salesmanship and marketing . ` ` Failure is a failure , not a dead - end , '' is one of many famous stock quotes .