Ella - AI Voice Agent for Post-Event Sales Follow-Up

Project Overview

This project was built to recover lost sales opportunities after live events. Many attendees stayed until the end of the webinar but did not purchase the course, and the team had no scalable way to follow up with them personally.

I designed Ella, an AI voice agent that automatically calls these attendees after the event, engages them in a natural conversation, addresses objections, and gathers insights from each call. The system integrates EverWebinar, GoHighLevel, n8n, Retell, Twilio (SIP trunking), and Google Sheets into a seamless automated follow-up pipeline.

The Problem
- Large number of webinar attendees did not purchase after the event.
- No structured or scalable follow-up process.
- Manual calls were impossible due to volume.
- Missed opportunity to understand attendee objections.
- No centralized tracking of post-event outreach.

The Solution
I built an automated workflow that activates immediately after each live event:
1. Data Retrieval from EverWebinar: Using EverWebinar APIs, n8n retrieves the list of attendees who stayed for the event but did not purchase the course.

2. Contact Management in GoHighLevel: The attendee details are sent to GoHighLevel:
- If the contact is new, a profile is created.
- If the contact already exists, duplicates are avoided.

3. Webhook Trigger from GoHighLevel : An automation inside GHL triggers a webhook that sends each contact, one at a time, into the calling workflow.

4. AI Voice Calls via Retell + Twilio:
- The contact details are passed to Ella, the AI voice agent built in Retell.
- A Twilio phone number connected via SIP trunking enables the agent to place real phone calls.
- Ella engages the attendee in a natural conversation, follows a sales-oriented script, and handles responses dynamically.

5. Appointment Handling: During the call, the AI agent can:
- Book new appointments.
- Reschedule existing ones.
- Cancel appointments when requested.

6. Call Summary & Tracking
After each call, a summary of the conversation is automatically logged into a Google Sheet for manual review and tracking by the team.

Key Features
- Automated identification of non-buyers after live events.
- Smart contact handling and deduplication in GoHighLevel.
- AI-powered outbound voice calls at scale.
- Natural, conversational sales follow-up using a voice agent.
- SIP trunking integration between Twilio and Retell.
- Automatic logging of call summaries into Google Sheets.
- Fully automated end-to-end workflow requiring no manual dialing.

Impact
- Enabled personal follow-up with hundreds of attendees automatically.
- Recovered potential lost sales opportunities after each event.
- Provided insights into attendee objections through call summaries,
- Eliminated the need for manual sales calls.
- Created a scalable post-event sales recovery system that runs after every webinar.