As America got richer (consumption) got more (complicated).With more income to throw around,people started spending more on services -- movies and travel,(mortgages) to buy houses,insurance to protect those houses,the occasional decadent weekend at a luxury hotel.Economists call this a shift in the demand pattern;Fortune calls it the main reason that 64 of this year’s top 100 are service companies.Over the next few years,only three of the ten fastest-growing (occupations)(software engineers,nurses,and computer support)pay middle-class salaries.The rest could be called,well,Wal-Mart kinds of jobs -- (cashiers),retail assistants,food service,and so on.In short,the service economy is delivering more good jobs than ever before.