How ReThink HK Achieved 52% CTR with WhatsApp Broadcasts and Omnichat for Event Registration

ReThink HK is Hong Kong’s unique annual event dedicated to accelerating sustainable transformation. By uniting top industry leaders, corporations, social enterprises, and NGOs, the flagship event helps organisations align sustainable practices across their value chain. For its sixth edition in September 2025, which aimed to welcome over 10,000 attendees, ReThink HK needed a communication strategy that was as innovative as its mission.

To meet this crucial need, ReThink HK implemented Omnichat’s WhatsApp Business API solution, viewing WhatsApp as a vital, direct communication channel for instant enquiries. The goal was to reach their extensive target audience for the flagship sustainable business forum and solutions expo, facilitating both event promotion and real-time support.

Challenges: High Labour Costs and Slow Email Response

Traditionally, event organisers rely heavily on emails and manual phone calls for crucial communications such as event registration, attendance confirmation, and reminder calls. However, this outdated approach presented several critical challenges for ReThink HK:

• Declining Engagement: Email open rates were dropping, and response times were often too long, leading to uncertainty in projected attendance figures.
• Wasted Manpower: Significant time and human resources were spent manually calling every attendee to confirm attendance and issue reminder calls, diverting staff from more strategic tasks.

Powering ReThink HK with Omnichat & WhatsApp Business API

Ranging from the implementation of the WhatsApp promotion strategy to the event launch, the entire digital transformation process was completed in just one month. This rapid transition was achieved because Omnichat’s WhatsApp Business API proved to be highly user-friendly and easy to adopt.

A Seamless and Personalised WhatsApp Journey

Driven by the need for a more direct support channel, ReThink HK chose to structure its customer journey within WhatsApp to maximise efficiency. This allowed the organisation to add a crucial communication channel, enabling customers to use WhatsApp for enquiries and eliminating the need for calls or emails. 

The journey began with the first step: proactively driving sign-ups by sending event registration invitations through highly visible Broadcast messages. Next, ReThink HK  precisely filtered and segmented the registered audience based on their chosen seminars or workshops. Following segmentation, the platform delivered timely and relevant reminder broadcasts to boost attendee turnout. Finally, all engagement metrics and confirmation statuses were collected and centralised in the backend, providing crucial data for analysis and optimisation.

Achieving Breakthrough Results with WhatsApp Broadcasts

ReThink HK leveraged the power of WhatsApp Broadcasts to promote event registration, incorporating clear Call-to-Action (CTA) buttons that enabled them to send personalised, targeted messages in bulk using rich media templates, all supported by real-time analytics. For instance, customers who clicked the “Register Now” button in the broadcast message were directed straight to the registration website form, while those who selected “Conference Prog” were taken to the official website for more detailed information. 

This targeted approach demonstrated the channel’s superiority, with the WhatsApp Broadcasts achieving a read rate of up to 86% and the CTA buttons driving an impressive click-through rate (CTR) of up to 52%.

Segmentation: Precise Audience Filtering

The segmentation capabilities were essential for managing the event’s complex structure, which included a total of 24 roundtable and workshop sessions at 3 locations across different timeslots. ReThink HK efficiently filtered customers from their database for targeted registration messaging, ensuring attendees only received relevant reminders for the specific seminars they signed up for.

Effortless Data Collection and Analysis

The WhatsApp journey was specifically designed for both effortless data collection and labor optimisation. The “Register Now” CTA button immediately recorded the number of leads expressing interest, providing the team with continuous, up-to-date oversight of their prospect pipeline. Furthermore, the “Yes, I will attend” button allowed attendees to confirm their attendance easily, which was critical in freeing the customer service team to be reallocated to handle more complex inquiries instead of making manual confirmation calls. 

Finally, by tracking comprehensive send, open, click, and conversion metrics in the backend, ReThink HK could accurately measure their ROI and optimise future event campaigns, which resulted in the team receiving nearly 200 messages in just two weeks, signifying a significant increase in proactive, two-way interaction with their customers.

“Omnichat’s WhatsApp solution really solved ReThink HK’s pain point for doing direct communication with our delegates before the event. We bypassed email limitations and manual calls with targeted broadcasts that achieved a 52% click-through rate. The seamless segmentation and automated CTA buttons streamlined registration and confirmations, saving us significant time and resources. The platform is intuitive and delivered immediate, impressive results, proving itself as an essential tool for modern event marketing. We are thrilled with the outcome and look forward to future collaborations,” said Chris Brown, Founder & CEO of ReThink HK.

Based on the exceptional results already achieved, with support from Omnichat, ReThink HK is open to considering more WhatsApp features in the future. Future plans involve deepening platform integration by incorporating features such as utilising the chatbot to help customers find event information and instantly answer frequently asked questions directly via WhatsApp, further enhancing their attendee experience.