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TL;DR: A Klaviyo win-back flow re-engages customers who stopped buying. A sunset flow suppresses the ones who never come back. Run them as one system: win-back makes the last honest pitch, and sunset protects your sender reputation from everyone who ignores it. Trigger on your real repurchase cycle, escalate the offer, and suppress after 90 days of silence.
A Klaviyo win-back flow is an automated email series that re-engages lapsed customers for Shopify brands, then hands anyone who stays silent to a sunset flow that guards your sender reputation. Most brands build one and skip the other. That's the mistake. You either win the customer back or you sunset them, and there's no third option that keeps your inbox placement safe.
Here's why this matters. Harvard Business Review found that winning a new customer costs five to twenty-five times more than keeping one you already have. Your lapsed buyers are the cheapest revenue you're not collecting. At the same time, people who never open your email drag down your engagement, and Gmail reads low engagement as a sign that your mail isn't wanted. So this flow does two jobs at once. It reactivates buyers worth keeping, and it flags the ones who need to go. This playbook covers when to trigger the flow, how many emails to send, what offer to use, and how to pass non-responders to a sunset flow without torching your list.
What's a win-back flow?
A win-back flow is an automated Klaviyo email series triggered when a past customer goes quiet for longer than their normal buying cycle. It sends two to four emails that remind them why they bought, then gives them a reason to return. The goal is a repurchase, not just an open.
Win-back targets people who have bought before, which separates it from a re-engagement campaign aimed at subscribers who never purchased. Because these people already trust you, it's one of the highest-value email automations you can run, even though Klaviyo's data shows it has the lowest engagement rate of any flow. That's expected. You're emailing people who already drifted. A small reactivation rate on warm buyers still beats cold acquisition on cost, since the odds of selling to an existing customer sit around 60 to 70 percent versus 5 to 20 percent for a new one.
When should it trigger?
Trigger the win-back flow at two to three times your average time between orders, not a flat 90 days. A coffee brand with a 30-day reorder cycle should wait 60 to 90 days. A furniture brand might wait a year. Match the timer to how often people actually buy.
The single biggest win-back mistake is copying someone else's 90-day trigger. If your customers reorder every three weeks, 90 days means you waited three cycles too long. If they buy once a year, 90 days means you're nagging people who aren't lapsed at all. Open your Klaviyo analytics, find the median time between a customer's first and second order, and set the trigger at roughly double that. You want to catch people right as they slip, while your brand is still fresh in their memory. The gap widens fast for consumables. A skincare buyer who normally reorders monthly is a red flag at 60 days, while a mattress buyer isn't lapsed until well past a year. When you can't tell, start at 90 days and adjust once you see how the flow performs.
The 4-email sequence
Klaviyo recommends keeping a win-back flow to about three emails, and most brands land between three and five spread over four to six weeks. Here's a four-email structure that works across Shopify stores:
- Email 1 (day 0): No discount. Lead with what they loved. Show their last product, its best benefit, and one review. Roughly a third of reactivations happen with no incentive, and every discount you skip protects margin.
- Email 2 (day 7): A soft nudge. Introduce a small offer, around 10 percent, or spotlight new arrivals and a best-seller.
- Email 3 (day 14): The real offer. Escalate to 15 to 20 percent off, or a gift with purchase for margin-sensitive brands.
- Email 4 (day 21): The breakup. Tell them plainly you'll stop emailing unless they click. This one doubles as the bridge into your sunset flow.
Escalation beats a flat discount because it stops training buyers to ignore the first email and wait for a better deal. If you want proof of what the emails themselves should say, Klaviyo's win-back examples show the pattern in action across real brands.
What offer should you use?
Start with no offer, then escalate. Lead the first email with value and social proof, add roughly 10 percent in the middle, and save 15 to 20 percent or a gift for the final non-responders. Escalating protects margin and outperforms a single flat discount.
A flat 20 percent on email one teaches your best customers to wait for the coupon. Worse, it hands margin to people who would have come back for free. Sequence the value instead. Remind first, incentivize second, and only go big for the holdouts who ignore everything else. For margin-sensitive brands, a gift with purchase or free shipping often converts as well as a percentage and costs less.
What's a sunset flow?
A sunset flow is an automated series that gives unengaged subscribers one last chance to interact, then suppresses them if they don't. It removes dead weight from your list so mailbox providers keep sending your email to the people who still open it.
Klaviyo treats sunsetting as an inbox-placement tool, not a punishment. Contacts who haven't opened or clicked in 90 days and haven't ordered in 180 (about 90 days for consumables, longer for durables) are the classic sunset candidates. Send one or two final emails, give a short grace period of three to ten days depending on how often you send, then suppress anyone who stays silent. Suppressed doesn't mean deleted. You keep the profile and its history. You just stop mailing them.
Win-back meets sunset
This is the part nobody writes down. Win-back and sunset aren't two projects. They're one pipeline.
Your win-back flow makes the last real attempt to reactivate a lapsed buyer. Everyone who ignores the whole sequence has told you something: they're done for now. That exact group is who your sunset flow should catch. A customer who opens email three but doesn't buy is still worth keeping. A customer who opens nothing across all four is the one to let go. Chain them together so the final win-back email feeds straight into sunset entry, and you never have to clean your list by hand again.
Get the handoff wrong in either direction and it costs you. Suppress too early and you cut off customers who were just between purchases, the ones a longer win-back would have saved. Never suppress and your unopened emails pile up until Gmail decides your whole list is low quality and pushes even your engaged buyers to spam. The benchmark data is blunt: the brand that mails fewer, more engaged people beats the brand that mails everyone. Across the Shopify stores we manage at CartStrings, tightening this handoff is one of the fastest ways to lift revenue and deliverability at the same time.
Set it up in Klaviyo
You'll build this with two flows and one shared definition of "unengaged."
- Define engagement first. Decide what counts as active. Opened or clicked in the last 90 days is a safe default. Everything downstream keys off this.
- Build the win-back flow. Trigger it off your repurchase cycle with a date-based or segment trigger, add your email series with time delays, and set a flow filter so anyone who places an order exits right away.
- Build the sunset flow. Trigger it when a profile crosses your unengaged threshold, send one or two final emails, add a grace-period delay, then use a conditional split on engagement to suppress the non-responders.
- Watch re-subscribes. If someone clicks or buys during sunset, pull them back into your active list so you don't lose a winnable customer.
Because both flows share your engagement definition, they stay in sync. Fix the definition once and the whole system updates. If you'd rather not wire the conditional splits yourself, a quick Klaviyo audit will show exactly where your current flows leak revenue.
The bottom line
A Klaviyo win-back flow and a sunset flow do far more together than either does alone. The win-back gives lapsed buyers a real reason to return, using an escalating offer that protects your margin. The sunset catches everyone who stays silent and clears them out before they drag your inbox placement down. Trigger on your actual repurchase cycle, not a borrowed 90-day default. Escalate the offer instead of opening with a coupon. And chain the two flows so your list cleans itself. Do that and you turn your quietest contacts into either recovered revenue or a healthier sender reputation. Both are wins. If you want this built and monitored for you, book a call with CartStrings and we'll map your win-back and sunset system to how your customers actually buy. For more tactics, browse our other Klaviyo guides.
Frequently Asked Questions
What is a win-back flow?
A win-back flow is an automated email series that targets customers who bought before but have gone quiet. It usually sends two to four emails over four to six weeks, starting with a reminder and ending with an offer. The goal is to earn a repurchase from people who already trust your brand.
When should it start?
Trigger the flow at two to three times your average time between orders. If people reorder every 30 days, start around 60 to 90 days of silence. If they buy once a year, wait far longer. A flat 90-day trigger fits almost no store, so use your own repurchase data.
How many emails?
Klaviyo suggests around three emails, and most Shopify brands run three to five. A common structure is a no-offer reminder, a soft nudge, a stronger offer, and a final breakup email. More than five rarely helps and risks annoying people who have already decided.
Win-back vs sunset flow?
A win-back flow tries to reactivate lapsed buyers with offers and reminders. A sunset flow gives unengaged contacts one last email, then suppresses them to protect deliverability. Win-back aims for a sale, and sunset aims for a clean, engaged list. They work best chained together.
Does suppressing help?
Yes. Mailbox providers like Gmail read low engagement as a sign your mail isn't wanted, which hurts inbox placement for your whole list. Suppressing people who never open means you mail fewer, more engaged contacts, and that reliably lifts open rates and placement.
