How to Automate Lead Calls with Voice AI (Retell AI + Make.com)
Most businesses lose 78% of leads by responding too slowly. This Retell AI + Make.com automation calls every lead within seconds of form submission, qualifies them with natural conversation, and logs everything in Google Sheets - with zero human intervention.
The Lead Response Crisis (And How AI Solves It)
Most businesses don't realize they're losing 78% of leads simply by responding too slowly. Research shows that contacting a lead within 5 minutes makes you 9x more likely to convert them - yet the average response time across industries is 47 hours.
This automation solves that crisis by combining three powerful technologies:
Key stat: Leads contacted within 5 minutes are 21x more likely to qualify compared to those contacted after 30 minutes (Harvard Business Review).
- Facebook Lead Ads captures prospect information instantly
- Make.com triggers the workflow within seconds of submission
- Retell AI conducts natural-sounding qualification calls
The result? Every lead gets a personalized call within seconds, complete with dynamic name recognition and industry-specific qualification questions - all while your sales team focuses only on the hottest opportunities.
Step 1: Building Your Voice AI Agent in Retell
The foundation of this automation is your AI sales agent in Retell. Unlike basic IVR systems, Retell agents understand natural conversation flow, handle interruptions gracefully, and adapt responses based on the prospect's answers.
At 4:32 in the video tutorial, you'll see the agent creation process:
- Create a "Single Prompt Agent" in Retell AI
- Paste your conversation script (template provided)
- Configure voice settings for natural delivery
- Test with dynamic variables like {{lead_name}}
Pro Tip: Use ChatGPT to generate your initial script, then refine it to keep calls under 2 minutes. The best performing scripts ask just 3-4 key qualification questions.
Step 2: Configuring Facebook Lead Ads
Facebook Lead Ads serve as the trigger point for this automation. At 8:15 in the video, you'll see how to:
- Create a new Instant Form in Facebook Business Manager
- Configure fields (minimum: name + phone number)
- Set up privacy policy and post-submit action
- Test the form to generate sample leads
This step ensures your automation has accurate contact information and context before making calls. The Facebook-Make.com integration passes all form data seamlessly to your workflow.
Step 3: Creating the Make.com Automation
The Make.com workflow acts as the central nervous system of this automation. At 12:47 in the video, you'll build:
- Trigger: Facebook Lead Ads "Watch Leads" module
- Action: Retell AI "Create Phone Call" with dynamic variables
- Configuration: API connection and phone number setup
This is where the magic happens - the moment a lead submits their information, Make.com instantly triggers Retell AI to place the call while passing all relevant context (name, source, etc.).
Technical Note: You'll need a $2/month Retell phone number for outbound calls. The tutorial shows exactly how to purchase and configure this.
Step 4: Setting Up Post-Call Analysis
What makes this automation truly powerful is the AI-powered post-call analysis. Starting at 18:20 in the video, you'll configure:
- Retell's post-call data extraction fields (qualification status, budget, timeline)
- Make.com webhook to receive analysis results
- Google Sheets integration to log all call details
- Filter to only update Sheets after full analysis
This creates a self-updating lead database where your sales team can instantly see which leads are hot, warm or cold - complete with conversation summaries and key details.
Bonus: Instant Alerts for Hot Leads
The tutorial includes a bonus section (22:45) showing how to set up instant Telegram alerts when the AI identifies a hot lead. This ensures your team can follow up immediately while the prospect is most engaged.
Key components:
- Filter to only trigger on "hot" qualification
- Telegram bot configuration
- Custom alert message with lead details
- Optional: CRM integration for automatic task creation
Real-world result: One solar company using this system increased their lead-to-appointment rate from 14% to 39% in 30 days.
Watch the Full Tutorial
For visual learners, the video tutorial at 6:18 shows the AI agent in action making a test call, while at 15:30 you'll see the exact Make.com configuration that makes it all work.
Frequently Asked Questions
Common questions about this topic
The AI agent calls within seconds of form submission - faster than any human sales rep could respond.
In testing, calls were placed within 3-5 seconds after the lead submitted their information through Facebook ads or web forms.
The AI agent collects key qualification details including homeowner status, roof type, budget range, timeline, and interest level.
It then categorizes leads as hot, warm or cold based on conversation analysis and stores all data in Google Sheets automatically.
Yes, Retell AI offers extensive customization options. You can choose from multiple voice options, adjust speech patterns, add background sounds, and fine-tune interruption sensitivity.
The script can be modified to match your brand voice and specific qualification questions.
In field tests, the AI demonstrated 92% accuracy in lead qualification compared to human sales reps.
The system analyzes conversation tone, response timing, and specific answers to categorize leads effectively.
Beyond Facebook Lead Ads and Google Sheets shown in the tutorial, the workflow can integrate with CRMs like HubSpot or Salesforce, messaging platforms like Slack or Telegram for alerts, and other lead sources including web forms and LinkedIn ads.
The base costs include $2/month for a Retell AI phone number and Make.com's free plan (which supports this workflow).
Additional costs may apply for higher call volumes or premium integrations, but most businesses spend under $50/month total.
Absolutely. The same workflow has been successfully adapted for real estate agencies, insurance providers, home services, and B2B SaaS companies.
The key is modifying the AI agent's script and qualification questions for your specific industry.
GrowwStacks helps businesses implement automation workflows, AI integrations, and scalable systems tailored to their operations.
Whether you need a custom workflow, AI automation, or a full multi-platform automation system, the GrowwStacks team can design, build, and deploy a solution that fits your exact requirements.
- Custom automation workflows built for your business
- Integration with your existing tools and platforms
- Free consultation to discuss your automation goals
Let Us Build Your Lead Conversion Machine
Every minute your leads wait decreases conversion odds. Our automation experts will implement this Retell AI + Make.com system for your business within 48 hours.