Short answer: when RRLabs is the better fit
Choose Churn Buster if you are ecommerce teams that want a polished email-only sequence. Choose RRLabs if you want retry timing scored per decline code, recovery messages delivered on WhatsApp as well as email, and a bill that does not grow every time recovery improves.
RRLabs connects to your billing provider read-only, verifies each failed-payment webhook with HMAC, and starts a reason-specific cadence automatically — no sales call, no percentage of the money it recovers.
How Churn Buster handles a failed charge
Churn Buster runs campaign schedules you configure by hand and reaches the customer over email, with a hosted card-update page. For an engaged customer with an expired card, that is often enough.
It stops working on the harder buckets. A do-not-honor block, a 3-D Secure confirmation that expired, and a payday-timing shortfall all need different windows and different wording; one schedule and one channel treats them identically.
How RRLabs handles the same charge
The decline code sets the schedule at ingestion: insufficient funds retries at 48 hours near payday, expired card waits 72 hours behind an update link, do-not-honor retries at 36 hours with an alternate-card prompt, and authentication required retries at 24 hours with WhatsApp first.
Copy is written for that exact reason by a four-tier engine — historical cache, primary model, low-cost fallback, deterministic template — so a message is produced even when every model is down. Each send is logged with model, latency and recovery score.
Cost comparison against Churn Buster
Tiered plans that scale with recovered revenue means your recovery tool gets more expensive precisely when it works. On $40,000 recovered per month, a 9% share is $3,600 — more than seven times the top RRLabs tier.
RRLabs charges the same $100, $250 or $500 whether it recovers nothing or six figures, plus $300 a month if you want the whole thing white-labelled under your own domain with DKIM signing and no watermark.
Migrating off Churn Buster without a gap
Connect your billing provider to RRLabs read-only and leave Churn Buster running. Nothing is sent yet.
Run one full billing cycle in shadow mode: RRLabs ingests every failure and generates the copy it would have sent, so you can compare projected recovery with your live baseline. Then pause Churn Buster's sequence, verify your sending domain and WhatsApp sender, and cut over. Sending both at once duplicates messages and depresses open rates.