This was seen in magazines for high school home ec teachers(and possibly others).Hoover was probably the best at promoting vacs to home ec depts and provided vacs for class rooms that would be updated every 2 years.Also a discount for the home ec teachers personal Hoover.Electrolux also provided vacs in the 50s.Leywt had ads for teachers in the 50s and Westinghouse promoted the ConvertoVac in the 60s in home ec magazines.