True Purpose
Shopper marketing leverages shopper's insights to create a marketing mix, which applied across the path-of-purchase needs to create incremental consumption increase, but as well longer lasting change in consumption behaviour in terms of habitual shopping change in favour of the specific brand and category, creating measurable ROI and growth. So the true, long term, and more important purpose is the shopping behaviour change. If there is no change in shopping behavior then there is no growth.