In pagan times, your 'genius' was the spirit that oversaw your whole life.
Later, it meant your general disposition. Only since the 19th century has it been possible to be 'a genius', someone with extraordinary, semi-divine powers. Those abilities - usually contrasted with mere 'talent' - are handy in business. They are also, strictly speaking, innate; but that hasn't stopped entrepreneurial types offering to make you a genius through books and seminars. That's perhaps because genius today has real commercial value. Where would the Virgin brand be without its peculiar 'genius'? And what about Steve Jobs, whose aura of omniscient cool saved Apple when it had gone rotten? In his booming high-street stores you can queue at the 'Genius Bar' and have your computer questions answered by semi-divine youths with 'Genius' for their job description.