Working a dead lead list at a fraction of the cost
An outbound voice agent that reactivated a dormant lead list. 30,000+ calls, cost per booked appointment down from $15 via ads to $4 to $5.
Representative interface. Built in-house on the client's own accounts; shown with sample data.
The situation
Auto Lead Kings had a large book of automotive leads that had gone cold. New appointments were coming mainly from a paid ad-to-appointment funnel, where each booked appointment cost about $15. The opportunity was to work the existing dormant list again, consistently and at a much lower cost per appointment, without the quality dropping.
What I figured out
The leads were warm enough (prior opt-ins) that the real problem was not lead quality. It was consistent, tireless follow-up at a cost that made sense. That is a case where voice genuinely fits: clear revenue tied to dialing volume, and a list worth working far more cheaply than buying fresh appointments through ads. So the move was to put an outbound agent on the dormant list.
What I built
An outbound voice agent on their own Retell, Twilio, and Supabase. It qualifies dormant leads and books appointments straight into the sales team's calendar. A rotating pool of phone numbers keeps it from getting flagged as spam, and retry logic works no-answers across several attempts. After each call the data flows from Retell to Supabase to n8n for CRM sync and a confirmation text. They got a branded dashboard for full visibility, and they own every account end to end.
The result
Over 30,000 calls shipped in production, a 10% appointment booking rate, and a cost of about $4 to $5 per booked appointment, down from the roughly $15 the same appointment cost through the paid ad funnel.
Stack
Retell (voice), Twilio (telephony and SMS), Supabase (database, edge functions, dashboard), n8n (CRM sync and follow-up). Client owns every account.