You set up a dunning tool to stop failed payments from eating your MRR. Six months later the tool is recovering $5,000 a month and sending you a $750 bill for the privilege. That's 15% of revenue you already earned, clawed back by a vendor for sending emails on your behalf.
This is the tradeoff most SaaS teams discover too late. Percentage-of-recovered-revenue pricing looks painless when you sign up and gets expensive fast when it works. Flat-fee dunning flips that math. Here's how the two models compare, and why most Stripe-first SaaS teams are better off paying a predictable monthly fee.
The two pricing models, plainly
Dunning vendors charge in one of two ways.
Revenue share. You pay nothing (or very little) upfront. When the tool recovers a failed payment, the vendor takes a cut, usually 10% to 30%. Churnkey, ProfitWell Retain (now Paddle Retain), and Gravy all use variations of this. The pitch: "We only win when you win." The reality: you pay forever on revenue you already had customers for.
Flat fee. You pay a fixed monthly price based on volume tiers (number of Stripe accounts, email sends, MRR bucket). Whatever the tool recovers, you keep. Rekko, Stunning, and Slicker all operate this way.
Both models can be reasonable. The question is which one costs you less over a year of normal operation.
The math that actually matters
Let's run it with realistic numbers. Assume you're a SaaS at $200K MRR. Industry data puts involuntary churn at around 9% of MRR for SaaS, so roughly $18,000 a month hits Stripe as a failed payment. A well-tuned dunning flow (email plus SMS, good retry cadence) recovers 60% to 80% of that. Pick 70% as a midpoint, which is $12,600 recovered.
Now apply each pricing model.
| Model | Monthly cost | Annual cost | % of recovered revenue kept |
|---|---|---|---|
| Revenue share at 15% | $1,890 | $22,680 | 85% |
| Revenue share at 25% | $3,150 | $37,800 | 75% |
| Rekko Essential (flat $49) | $49 | $588 | 99.6% |
| Rekko Pro (flat $129) | $129 | $1,548 | 99% |
At $200K MRR, the difference between a 15% cut and a flat $49 fee is over $22,000 a year. At $500K MRR the gap widens to roughly $55,000. The better your recovery tool performs, the more painful revenue-share pricing gets, which is a weird incentive structure when you think about it.
"But revenue share aligns incentives"
This is the standard defense, and it's half true.
Revenue share does mean the vendor has skin in the game. If they build a bad product, they earn nothing. That's a legitimate argument when you're evaluating a brand new vendor with no track record.
But dunning is not a mysterious art. The playbook is well understood: catch the webhook, retry on the right cadence, send a sequence of emails, add SMS, include a pre-authenticated update link. Any competent vendor can execute this. You're not paying 15% for magic, you're paying 15% because that's what the pricing page says.
Flat-fee vendors still have skin in the game through churn. If Rekko stops recovering your failed payments, you cancel. The incentive exists, it just doesn't scale linearly with your MRR.
When percentage pricing actually makes sense
Credit where it's due. Revenue-share pricing is a reasonable fit for a few situations.
You're pre-revenue or very small. If you're doing $2K MRR, a flat $49 fee is meaningful and a 15% cut on $140 of recovered revenue is $21. Percentage wins on absolute dollars until you hit around $5K to $10K recovered per month.
You want zero procurement friction. Some teams genuinely prefer no fixed line item on the P&L. Revenue share shows up as contra-revenue or COGS and never requires a budget conversation.
The vendor bundles services. If you're paying for cancel flows, CS automation, and retention strategy alongside dunning, a percentage deal can be fair for the total scope.
Outside those cases, flat fee almost always wins on total cost of ownership once you're past a few thousand dollars of recovered revenue per month.
What to watch for in flat-fee pricing
Flat fee is not automatically cheaper. A few things to check before you switch.
Volume caps. Most flat-fee tools tier by email sends, SMS credits, Stripe accounts connected, or MRR band. Read the overage terms. A $29 plan with a 1,000-email cap gets expensive if you blow past it every month.
SMS handling. SMS lifts recovery rates 30% to 40% over email alone, so you want it included. Some flat-fee tools bundle SMS, others pass through Twilio costs at cost, and a few bolt it on as a separate subscription. Rekko does pay-per-use SMS on top of the flat plan, which keeps the base price low while still letting you run multi-channel sequences.
Setup cost. Flat-fee tools usually have zero implementation fees. Percentage tools sometimes have them, sometimes don't. Enterprise billing platforms like Recurly or Chargebee can hit you with implementation fees that dwarf the ongoing cost for the first year.
What's actually included. Cancel flows, payment method update portals, analytics dashboards, A/B testing, segment targeting. If you need only dunning, don't pay for the whole retention suite.
A practical comparison
Here's how the main dunning tools land on pricing model.
| Tool | Pricing model | Starting price | Takes % of recovered revenue |
|---|---|---|---|
| Rekko | Flat fee | $29/mo | No |
| Stunning | Flat fee | $50/mo | No |
| Slicker | Flat fee | $49/mo | No |
| Churnkey | Hybrid (tiered + %) | ~$100/mo | Sometimes |
| Paddle Retain | Bundled with Paddle | Included | Yes (via Paddle's MoR fees) |
| Gravy | Revenue share | Custom | Yes |
| Baremetrics Recover | Flat add-on | ~$50/mo | No |
| Recurly | Platform fee + % | Custom | Indirectly (transaction %) |
| Chargebee | Platform fee + % | $249/mo | Indirectly (0.75% transaction) |
Stripe Billing's Smart Retries is a different category. It's included with Stripe at no extra percentage, but its recovery rate sits around 30%, well below what a dedicated tool delivers. More on that in our Stripe Smart Retries pricing breakdown.
The hidden costs of percentage pricing
Beyond the obvious math, there are a few second-order effects of revenue-share pricing that rarely show up in the sales pitch.
Forecasting gets harder. Your dunning bill becomes a function of your involuntary churn rate, which is a function of your customer base's card health, which is a function of macro factors you don't control. When a cohort of customers hits expired cards in the same month, your recovery volume spikes and so does your vendor bill. Finance teams don't love unplanned expense variance.
Optimization upside shrinks. Say you spend a sprint tuning your dunning sequences. You move recovery rate from 60% to 72%. Under a flat fee, that 12-point lift is 100% yours. Under a 20% revenue share, the vendor captures roughly a quarter of your improvement. You did the work, they got paid.
Contract negotiation gets political. Enterprise revenue-share deals usually come with MRR-band pricing that resets annually. As you grow into the next band, your rate changes. Every renewal becomes a re-negotiation, and the vendor knows switching costs are high because you've built sequences and templates inside their tool.
Switching costs compound. The longer you stay, the more operational muscle memory you build around the vendor's UI, reporting, and integrations. Moving to a flat-fee alternative is always technically possible, but the inertia is real. Starting with flat-fee from day one avoids the lock-in.
None of these are dealbreakers on their own. Together they're the reason most SaaS teams that start on revenue-share eventually look for alternatives.
How to switch without breaking anything
If you're currently on a percentage-based dunning tool and considering a move, the migration is less scary than most teams expect. The rough playbook:
- Export your current sequences. Copy the email templates, subject lines, and timing rules out of your current tool. These are your institutional knowledge and they port to any new tool in under an hour.
- Connect the new tool to Stripe in parallel. Rekko (and most competitors) use OAuth to read Stripe events. You can run both tools pointed at the same Stripe account during a test window.
- Pick one product or segment to cut over first. Don't flip the whole customer base on day one. Move a subset, watch the recovery numbers for a week or two, then expand.
- Disable the old tool once you're confident. Recovery rates should be stable or better. If they're not, you have data to debug before you're fully committed.
Total elapsed time: typically a week, maybe two if you're being cautious. Compared to the annual savings we showed above, that's a very short payback period.
Rekko's take
We built Rekko on flat fees because we were tired of watching friends at other SaaS companies hand over 10% to 20% of recovered revenue for a tool that was basically sending emails and SMS. Our pricing is public: $29/mo for Starter, $49/mo for Essential, $129/mo for Pro. SMS is pay-per-use on top, so you only pay for what you send.
At $200K MRR running a typical dunning flow, you'd pay us $49 a month and keep roughly $22,000 a year compared to a 15% revenue-share tool. That's the whole argument.
If you want to see the full pricing breakdown or read how we compare to specific competitors, we have detailed pages on Churnkey, Paddle Retain, and Stripe Billing.
Try Rekko free
- Email plus SMS recovery in one tool
- Flat monthly pricing, no revenue share, ever
- 5-minute Stripe setup
- Keep 100% of what you recover
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