SaaStock Paris - How to optimize customer retention in SaaS? Insights from Aircall and Lemlist

Inside SaaS — How Aircall and lemlist Drive Retention and Expansion to Build Sustainable Growth

Jonathan Anguelov (Aircall) and Guillaume Moubeche (lemlist) shared their approaches to retention, churn, and expansion — the two pillars of lasting growth in SaaS.
Two very different stories: Aircall, with 850 employees, $130M ARR, and a sales-led motion; lemlist, with $20M ARR, fully bootstrapped and product-led.
A candid discussion on what drives Net Revenue Retention (NRR), how to structure Customer Success, and the real levers of expansion.

1. Retention as a Core Metric

“Net retention is the number one metric in SaaS.” — Jonathan Anguelov

Jonathan points out that many founders focus on top-line growth, which can be misleading:

“It’s easy to grow fast with a great sales machine. But if you have negative net retention, you’re building a giant on sand.”

At Aircall, NRR historically sat between 110% and 130%.

“Between 110 and 130% — that’s best-in-class. In today’s environment, being at 100% is already strong.”

A high NRR means solid product adoption, long-term stickiness, and expansion potential.

2. Understanding Churn Before Fighting It

At lemlist, churn was the first challenge of a pure self-serve model.

“At the beginning, we were losing 15% MRR per month. Many small clients canceled as soon as their activity slowed down.” — Guillaume Moubeche

Over time, the team learned to segment churn into three categories:

• Seasonal churn, linked to activity cycles;
• Product churn, tied to poor perceived value;
• Structural churn, from the wrong customer fit.

“We realized you can’t treat a solo founder who prospects three months a year like a 20-rep sales team.”

3. Expansion as the Hidden Growth Engine

“Expansion is what takes you from $20M to $200M ARR.” — Jonathan Anguelov

At Aircall, growth was largely driven by account expansion:

“A client starts with support, then sales, then marketing. That’s how we scaled.”

At lemlist, the same pattern holds:

“Expanding a customer from 2 to 20 users is ten times easier than closing 10 new clients.”

Expansion relies on three fundamentals:

1. Clear, user-based pricing,
2. A product that’s essential daily,
3. A proactive Customer Success mindset focused on selling value.

4. Pricing — the Most Underused Retention Lever

“We moved from packaged plans to per-user pricing. Retention jumped by 10 points.” — Aymeric, Agorapulse

All three founders agree: pricing drives retention.
Guillaume notes:

“When we unified pricing and removed grandfathered plans, our NRR hit 120%.”

Jonathan adds:

“We’ve never raised prices for existing clients — and that’s a mistake. Even 5% yearly is healthy.”

A good pricing model is simple, transparent, value-aligned, and regularly updated.

5. Customer Success as a Revenue Engine

“Customer Success is a commercial role.” — Jonathan Anguelov

At Aircall, each CSM manages between €1.8M and €2.4M ARR, depending on customer segment (from 50 to 300 accounts).

Key priorities include:

• monitoring support tickets,
• identifying under-usage,
• anticipating churn before it happens.

“A customer opening three support tickets in two weeks is a red flag.”

Guillaume shares a similar mindset:

“We track user activity, campaign performance, and engagement. If metrics drop, we trigger educational content or outreach before churn hits.”

6. From Reactive to Proactive

Both founders insist on a proactive culture in Customer Success.

“Stop being reactive — success is about predicting issues before they arise.” — Jonathan Anguelov

Guillaume explains:

“We connect our product data to Customer.io and Intercom. When a customer’s results drop, they automatically receive helpful content or a webinar invite.”

Automation allows lemlist to scale retention efforts across thousands of accounts.

7. Measuring the Impact of Customer Success

“Measure everything — but know why you’re measuring it.” — Jonathan Anguelov

At Aircall, CSM performance is tied to:

• portfolio expansion (80%),
• contract annualization (20%), which reflects account stability.

Guillaume takes a lighter approach:

“I don’t want CSMs buried in dashboards. Their mission is to make users successful — that’s the only KPI that matters.”

8. Spotting Early Warning Signs

Both leaders share the same analytical reflexes:

• declining active users,
• rising support volume,
• poor feature adoption,
• or a champion leaving the company.

“When your champion leaves, you need every conversation documented so the relationship survives.” — Jonathan Anguelov

9. Expansion as a Company-Wide Reflex

At Aircall and lemlist, expansion isn’t a department — it’s a mindset.

“The CSM identifies, the Sales rep closes. They share both the bonus and the responsibility.”

Guillaume takes it further:

“At lemlist, everyone gets the same bonus — regardless of the role. We win as a team.”

A model that encourages every department to focus on long-term customer value, not short-term bookings.

10. Key Takeaways

• NRR is the king metric — growth without it doesn’t last.
• Pricing is strategic, not operational.
• Customer Success drives revenue, not just support.
• Expansion is cheaper than acquisition.
• Proactivity must be cultural, not procedural.

“A company with 120% NRR can grow forever — even without raising funds.” — Guillaume Moubeche