Copyhackers
Joanna Wiebe earns a place on this list because conversion copywriting is one of the highest leverage parts of CRO, and she helped define that field for modern marketers. As the creator of Copyhackers, she has taught thousands of founders, copywriters and marketers how to write copy that moves people toward action. Her influence sits at the intersection of messaging, research, SaaS growth and landing page performance, which makes her an important CRO figure even though her core platform is copywriting rather than a traditional testing agency.