After the first Hoover vacuum cleaner, the Model O, was invented in 1907, it rose to become the preeminent brand in the burgeoning electric vacuum industry. The Hoover Company, and its chief product, changed a lot in the twenty years (1945-1965) between these two ads.
Life, June 1945 - 'Room just decorated?' 'No, Hoover just serviced.'
Family Circle, December 1965 - 'Hoover' just doesn't mean vacuum anymore! Sadly, household appliance advertising doesn't look so mod these days.
You can find seven more Hoover print ads spanning 1934-1952 here. And check out The Vintage Hoover Emporium.