Put simply, market surveillance is the process of finding out what your competitors are doing. Changes that your competitors make to their business may be based on market research they have undertaken that has identified a genuine need. Identifying changes with competitors early and refining your offering can often limit any damage to your business.
Do remember not to limit your competitor research only to other pharmacies. Medical practices may be competing for services with pharmacy and supermarkets and health and beauty retailers are competing for the retail spend in the community pharmacy.