How did the blender change society?

The fast production of milk shakes and other frothy drinks for consumption in cafe-style shops in the United States - soda fountains - was a major impetus behind the successful development and manufacture of blenders and related tools; it would be true to say the popularity of the soda fountain had a marked influence on society, an influence which continued and expanded with time.

Commercial kitchens used electrical equipment such as blenders and, later, food processors, well before their introduction into households, and this made commercial production of food more economical owing to greater speed and therefore reduction in staff-time required to make finished products.

Recipes and preparation methods were developed which wouldn't realistically have been possible without electrical equipment.

It is doubtful the introduction of the electric blender into domestic kitchens would have had much significant effect upon society; blenders mostly did the same job as kitchen tools and methods already in use, only faster and with less effort.