Inbox Inflation: Why Retention Marketing Requires More Than Just More Emails

Hey everyone,

Welcome back for another bite to chew on.

These days, a good retention program is a must for long-term survival.

Everyone should try to be first-purchase profitable, of course. BUT the second, third, and fourth purchases are what really fuel growth. 

Every brand we know is racing to push retention. Which means inbox competition is vicious. 

Consumers are opting out in record numbers. And Gmail just made it even easier to unsubscribe. The era of “just send more emails” is over.

If your retention playbook hasn’t evolved, it’s about to get buried in the inbox.

🍽️ On the Menu:

• Why inbox fatigue and deliverability issues are spiking

• Where the old retention playbook falls short vs what’s working

• The Modern Retention Stack for 2025

Let’s go 🚀

We Finally Switched to Klaviyo. Here’s Why.

Obvi scaled past $40M in annual sales last year. And…we started running into the limits of our marketing automation platform.

Our needs grew beyond just “campaigns and flows.” We needed real-time data, smarter segmentation, zero outages, and a system that could grow with us.

That’s why we decided to move to Klaviyo.

Now our retention marketing is powered by a true CRM, custom-built for B2C. That means we can personalize in real time based on comprehensive customer data.

✅ Here’s what we gained → 

• Unified customer profiles that update automatically

• Smarter segments based on actual onsite + purchase behavior

• Email and SMS campaigns that work together seamlessly

• Automations that scale without extra complexity

A strong retention program has never been more important than right now.

And the foundation for strong retention is a system that enables you to fundamentally get your customers at scale. 

So if it feels like you’ve outgrown your current platform, it’s probably time to upgrade.

→ Find out how Klaviyo is more than just email and SMS

📊 The Retention Gold Rush (And Fallout)

Retention used to be a “nice-to-have.”

Now it’s the difference between growing and slowly bleeding out.

As ad costs keep climbing, more brands are waking up to the fact that repeat purchases are where the margin lives. So everyone’s leaning harder than ever on email and SMS to re-activate past buyers.

But that means…

• Email volume has exploded (+33% YoY in 2024)

• SMS opt-out rates are quietly climbing (73% of consumers unsubscribe from an SMS marketing if they receive too many messages)

• Unsubscribes from automated flows (not just blasts) have doubled

🥊 Customers aren’t just overwhelmed. They’re actively fighting back.

Gmail and Yahoo introduced stricter rules this year. You now need SPF, DKIM, and DMARC compliance, one-click unsubscribe headers, and complaint rates below 0.3% to stay in the inbox. 

Miss those standards = good luck landing in primary. 😬

⚡️ Why the Old Retention Playbook Fails

Let’s be honest: most brands' retention strategy still looks like...

• Same offer, every week (a bunch of discounts)

• Same flow for every customer

• Same subject line format for months

What’s worse is that we see brands stacking automations on top of each other without prioritization. '

So a customer who just bought might get:

• A cart abandonment reminder

• A welcome series

• A product quiz flow

• A loyalty email

... all within the same 48 hours.

We’ve been there. At Obvi, we used to just blast everything at once, too.

Here’s what we learned: retention isn’t just about sending more emails. It’s about sending the right email at the right time, to the right person, with the right message.

That only happens when you stop thinking like a broadcaster and start thinking like a relationship builder.

🧩 What’s Working for Us (Real Retention Wins)

We’ve spent the last few months reworking retention at Obvi. A few changes made a huge difference:

1. Motivation-Based Segmentation
We stopped guessing why people buy. Instead, we asked.

When someone buys collagen from us, we capture intent: are they focused on beauty, joint support, or weight goals?

Each path gets its own follow-up journey. Beauty buyers see different content, testimonials, and offers than performance buyers.

The result = +22% repeat purchase rate.

2. Flow Prioritization
We built a simple hierarchy:

1. Revenue recovery (abandonment flows)

2. First impressions (welcome)

3. Relationship building (post-purchase)

4. Win-back campaigns

This way, if a customer qualifies for multiple flows, we know which one matters most.

3. Gamification and Mystery
We made abandoned cart emails feel like treasure hunts. Instead of "You forgot something," we used copy like:

"You left something behind... but there might be a surprise waiting."

We tested mystery gifts, scratch-off reveals, and progress-based rewards. Engagement went up 60%.

4. Platform Shift to Klaviyo
We recently moved to Klaviyo for a specific reason: it’s no longer enough to send emails and texts. We needed infrastructure that helps us really understand our customers.

Klaviyo’s CRM capabilities let us segment based on behavior, lifecycle stage, and purchase motivation, not just past orders or subscription date. It’s how we deliver more relevant messages without burning out our list.

See your customers clearly. Klaviyo helps unify your customer data so you can segment, personalize, and grow.

Stop Guessing. Start Segmenting Smarter →

🔄 The Retention Stack for 2025

To keep your brand from becoming white noise in 2025, here’s how to evolve your retention engine:

✅ Relevance > Volume

Sending weekly blasts to your entire list might keep your ESP stats busy, but it can kill engagement.

Start by suppressing cold subscribers, and use click behavior to trigger your next message.

Example: if someone clicks a product but doesn’t buy, skip the generic blast and follow up with that product’s review.

✅ CRM-Grade Intelligence

Basic segmentation is table stakes. 

At this stage, your ESP needs to behave more like a CRM, tracking AOV, churn risk, and time-to-repeat. 

Example: Klaviyo’s predictive tools, for example, let us preemptively win back high-value customers before they disengage.

✅ Prioritized Automation

More flows = more overlap = more confusion. Don’t just stack automations, rank them. 

If someone is in an abandoned cart flow, suppress your welcome series. 

💡 Automations need a logic tree, not just a trigger.

✅ Multi-Channel Sync

SMS and email are better together, but only if they’re coordinated. 

Use SMS for urgency (e.g. low stock or expiring promo), and email to build the story and deepen engagement. 

Remember to set rules to avoid hammering the customer with both in a single hour.

🔧 Bonus: Run This 3-Step Retention Audit

1. Are your flows prioritized?
If someone qualifies for three automations, which one fires first? If you don’t know, that’s the problem.

2. Are you still batch-and-blasting?
Look at your segments. Are they based on behavior and intent, or just age on a list?

3. When did you last clean house?
Check your engagement. Who hasn’t opened in 90 days? What’s your click rate vs. unsubscribe rate? 

Prune dead weight to improve inbox placement.

In short, if your retention playbook hasn’t really changed since 2023, it’s almost certainly leaking revenue.

🧰 Operator Toolbox

Klaviyo - Evolve your retention program from basic spray and pray to something that’s smarter, targeted, personalized, and profitable. See what’s hiding in your customer data →

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