The exposition is the plot element that will provide background information, introduces main characters, and always establishes conflict.
Most likely to look at the cover, to view the name title, etc. or even to view the publisher or authors of the titles. You will also probably be brought in by the headlines and previews shown on the front cover.
I think they do.
negatives:
might stereotype/group things and people wrong
might cost friendships depending on person
could cause disagreements
positives:
helps group and organize things
using creativity to think of a category