Use of 'at large'
Marketing is the activity, set of institutions, and processes for creating, communicating, delivering, and exchanging offerings that have value for customers, clients, partners, and society at large
What difference does it make if I cut at large in the sentence above?
Solution 1:
At large means 'in general'. In your example it contrasts the wider society with the smaller groups that precede it. Its removal would to that extent diminish the impact of the sentence.