Final answer:
The primary purpose of campaigns related to surfboard sales and lesson sign-ups is to drive sales and sign-ups, ultimately increasing revenue and customer base for the business.
Step-by-step explanation:
The primary purpose of campaigns in relation to surfboard sales and lesson sign-ups is c) Driving surfboard sales and lesson sign-ups.
Effective marketing campaigns are targeted to achieve this main goal by attracting new customers and motivating them to make a purchase or register for a service.
By focusing on both, businesses not only boost their revenue through direct sales but also build a customer base for future sales and potentially establish a long-term relationship with their clientele.