The boss of a national sports discount company has revealed the two things that have helped him create a £12m company.   David Hoskins, owner of Sportsmania, said the location of his stores, on industrial estates, are the closest thing he can get to a factory outlet. Mr Hoskins said shopping on industrial estates makes people expect to be shopping for less. And he said franchising 12 of his 18 outlets has enabled the five-year-old business to expand quickly.