Joe Frazer: "A cultural shift is required in many organisations to unlock volume within social platforms."
Equality Media, King Kong, Tracksuit, and PMG rounded out the top five.
The picnic was attended by The Pinnacle Foundation's CEO, Queer Town's founder, and UnLtd's GM.
The incumbent is independent agency Half Dome, which has serviced the account since August 2021.
Cosstick's appointment will see co-founder and current head of strategy Will Harms formally move into the role of head of clients.
The independent agency also appointed Riccardo Ilari as SEO manager.
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Gellibrand and Akimana share their perspectives, thoughts and opinions
Paul Wilkinson: "I've learnt so much in the last 2 years that I will carry with me for a long time"
Frazer: "At the end of the day, people pick people they want to work with."
The Vitasoy appointment is effective from 1 July
Ecosa has appointed Half Dome to undertake full-service media support
"I'm thrilled to be joining Half Dome and working with such a talented and passionate team"
"Half Dome is no longer scrappy, lucky, or any other motifs defining start-ups"