What I’ve learned from mergers and integrations: Three lessons companies can’t forget

After participating in mergers and acquisitions (M&A) over the past few years, I've come to realize that while every deal is unique, the patterns of success and failure are surprisingly consistent.

Mergers are almost always driven by a compelling value proposition: expanding capabilities, entering new markets, acquiring technology, increasing scale or enhancing competitive advantage. At their core, they are deeply rooted in financial logic. The first conversation is often about the potential impact on the P&L—synergies, efficiencies and growth.

But here's the catch: while the end goal is a stronger, more profitable company, how you get there matters just as much as where you're trying to go.

According to a frequently cited Harvard Business Review study, somewhere between 70% and 90% of mergers fail during the post-merger integration (PMI) phase. That's an astonishingly high rate. It's not because the strategy was flawed or the financials didn't work out, but it's because execution failed.

The integration phase is where the real work begins. Several easily overlooked but critical factors can make or break a merger's success in this phase. Here are three of the most important lessons I've learned:

1. Invest in business readiness; it's not optional

No matter how brilliant your strategy or how clean your financial model is, execution lives and dies by business readiness.

I've seen organizations charge ahead with integrations only to hit roadblocks because teams weren't adequately prepared for what was changing, let alone why or how.

Business readiness is broader than just training or change management; it's the full scope of operational awareness and alignment. It's asking:

• What's changing in the current vs. future state?
• Who is impacted, and how?
• What are the customer, business and financial implications?
• What mitigation strategies are in place?
• Who owns the transition, and how are we tracking it?

This includes seemingly minor changes, like removing a rarely used feature that <1% of customers rely on. That might not sound like a big deal, but if that 1% includes your most vocal or highest-revenue clients, you have a problem.

Or take something like billing. Even small shifts in timing, language or format can trigger a wave of customer service tickets or payment delays. That's revenue leakage waiting to happen.

A strong business readiness team operates like air traffic control. They're not flying the planes but coordinating every takeoff and landing to prevent collisions. They help everyone from engineering to finance to customer support understand what's coming, prepare for it and respond accordingly.

2. Don't overestimate the strength of your customer experience

It's common to deprioritize customer experience activities during M&A, especially when resources are pulled in every direction. There's always a long list of "must-dos": aligning systems, rationalizing product portfolios, integrating teams and closing books. Compared to those, things like customer onboarding flows, FAQs or functionality consistency may be overlooked with shifting priorities.

But here's the truth: if the merger impacts the customer in any way, primarily through systems, branding, billing or service delivery, the customer experience must be preserved at a minimum or ideally improved.

Customers should not feel the "cost" of your integration behind the scenes. The ideal scenario is that their experience is either the same or better, seamless, intuitive and value-added.

The key here is communication. Don't assume you know what customers want or how they will react. This is where A/B testing and customer insights are invaluable. You need to understand how different segments of your customer base are responding to the proposed changes. Tailor your messaging, test rollout strategies and invest in proactive customer service to mitigate confusion or friction.

Failing to do this risks creating gaps between expectation and reality, and even minor issues can snowball if your customers lose trust.

3. Watch out for the "poke-the-bear" effect

Imagine a company rolls out a change, a new login process, a rebranded invoice or an updated pricing structure. It seems minor on paper, but suddenly, churn spikes.

Why? Because the customer was reminded they were a customer.

I call this the "poke-the-bear" effect. You might have a passive, low-maintenance customer who hadn't thought much about your service. But now, due to a change prompted by the merger, they're forced to notice. And once they notice, they reevaluate. Maybe they realize they're not using the service anymore. Maybe they start comparing prices. Maybe they'll finally take action on that cancellation they've been putting off.

Involuntary change is risky.

To manage this, you need to anticipate where friction could occur and have mitigation strategies ready. This might mean proactively communicating the value of the new combined offering. It might involve providing incentives or discounts to customers impacted by key changes. Or even deploying dedicated support teams to high-risk segments.

The goal here isn't just to stop churn, it's to turn a moment of disruption into a moment of value.

Final thought: M&A is more than financials 

It's tempting to think that a successful merger is just about the numbers. And yes, financials matter. They always will. But behind every line item on a P&L is a person—a customer, an employee, a partner—whose experience will define whether that value is ever realized.

If there's one thing I've learned, the real work begins after the deal is signed. And while no integration is ever flawless, the best ones are those where leadership treats customer experience, churn mitigation and business readiness with the same rigor and focus as balance sheets and board decks.

Because that's how you go from "signed" to "successful."

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