Flows vs Campaigns in Klaviyo: When to Use Each

Every week, I see brand owners make the same mistake in Klaviyo. They build a campaign when they should have built a flow. Or they set up an elaborate flow for something that should have been a one-time blast. And then they wonder why their email revenue isn't growing the way it should.

Here's the thing: flows and campaigns aren't interchangeable. They're fundamentally different tools designed for fundamentally different jobs. Using the wrong one doesn't just waste your time — it actively hurts your performance.

I'm going to break down exactly when to use each one, the gray areas where it gets confusing, and the framework we use at GOSH Digital across 150+ Klaviyo accounts. No fluff, no filler. Just the decision tree you need.

The Core Difference (Simple Version)

Flows are automated. They trigger based on something a person does (or doesn't do). Someone abandons a cart? Flow triggers. Someone makes a purchase? Flow triggers. Someone joins your list? Flow triggers. You build it once, and it runs forever until you turn it off.

Campaigns are manual. You decide to send them. You pick the audience, write the email, schedule it, and hit send. They go out once to the people you selected. Done.

That's the mechanical difference. But the strategic difference is what matters.

Flows respond to individual behavior. They meet the customer where they are in their journey, at the exact moment something happens. Campaigns broadcast a message to a group. They're about what your brand wants to say, not about what the customer just did.

Both are necessary. Neither replaces the other.

When to Use Flows (The Behavior-Based Triggers)

Use a flow whenever the email should be triggered by a customer action. Here's the complete list of flows that should exist in every serious Klaviyo account:

Revenue-Critical Flows (Build These First)

• Abandoned Cart: Triggered when someone adds to cart but doesn't purchase within a set window. This is typically your highest-revenue flow. If you only build one flow, build this one.
• Browse Abandonment: Triggered when someone views a product but doesn't add to cart. Lower intent than cart abandonment, but high volume makes up for it.
• Welcome Series: Triggered when someone subscribes to your list. This is your first impression — don't waste it on a generic "thanks for subscribing."
• Post-Purchase: Triggered after an order is placed. Confirmation, shipping, review request, cross-sell. The full sequence.

Retention Flows (Build These Second)

• Winback: Triggered when a previous customer hasn't purchased in X days (usually 60-120 depending on your product cycle).
• Sunset: Triggered when a subscriber hasn't engaged (opened or clicked) in X days. This protects your deliverability.
• Replenishment: Triggered based on expected product usage timeline. If your product lasts 30 days, send a reminder on day 25.

Lifecycle Flows (Build These Third)

• Birthday/Anniversary: Triggered by profile date fields. Personal touch that drives goodwill and purchases.
• VIP Thank You: Triggered when a customer crosses a spending threshold. Acknowledge your best customers.
• Back in Stock: Triggered when a product a customer wanted becomes available again.
• Price Drop: Triggered when a product a customer viewed drops in price.

The common thread: every flow responds to something the customer did. The email wouldn't make sense if it arrived at a random time. "Hey, you left items in your cart" only works if they actually left items in their cart.

When to Use Campaigns (The Brand-Driven Messages)

Use a campaign whenever the email is about something your brand wants to communicate, regardless of individual customer behavior.

Promotional Campaigns

• Flash sales and limited-time offers
• Seasonal promotions (Black Friday, Valentine's Day, Back to School)
• Sitewide discounts
• Bundle deals and limited-edition launches

Content Campaigns

• New blog post announcements
• Brand storytelling and behind-the-scenes
• Newsletter sends
• Educational content
• Industry roundups

Product Campaigns

• New product launches
• Collection announcements
• Restocks of popular items (to your full list, not just back-in-stock waitlist)
• Product feature highlights

Company Campaigns

• Brand milestones ("We just hit 100,000 customers")
• Team announcements
• Policy changes (shipping, returns, pricing)
• Holiday messages

The common thread: these emails make sense regardless of what the individual customer did recently. A Black Friday sale announcement doesn't need a behavioral trigger. Everyone on your list should know about it.

The Gray Areas (Where People Get Confused)

Here's where it gets tricky. Some situations could go either way. Here's how we think about them:

New Product Launch

Most brands send a campaign. That's fine for the initial announcement. But consider building a flow too. If someone viewed the pre-launch page, or if they bought products in the same category before, a flow can deliver a personalized "this was made for you" message that hits way harder than a generic blast.

Our approach: Campaign for the broad announcement. Flow for the personalized follow-up to high-intent segments.

Sale Events (BFCM, Seasonal)

Definitely campaigns for the main announcements. But layer in flows for the behavioral stuff during the sale window. Someone who browses during your sale but doesn't buy? That's a flow opportunity. Someone who adds a sale item to cart and bails? Flow.

Our approach: Campaign for the "Sale is live" and "Sale is ending" messages. Flows for all the abandoned browse and cart activity during the sale period.

Re-Engagement

This confuses people the most. You want to wake up your inactive subscribers. Flow or campaign?

If you're targeting people based on a time-since-last-engagement metric (hasn't opened in 90 days), that's a flow. The trigger is the passage of time relative to their last action.

If you're running a one-time "We miss you" push to a specific segment as a special promotion, that's a campaign.

Our approach: Build a sunset flow for ongoing re-engagement. Run occasional campaigns for big "come back" pushes with exclusive offers.

Educational Content Based on Purchase

Someone bought a coffee grinder. You want to send them a brewing guide. Flow or campaign?

Flow. Always. The trigger is the purchase. The content is relevant to what they bought. The timing should be based on when they're likely to receive and use the product, not on when you feel like sending it.

The Revenue Split: What Good Looks Like

Here's a benchmark that might surprise you. For a well-optimized Klaviyo account, the revenue split should look something like this:

| Source | % of Email Revenue | Notes | |---|---|---| | Flows | 40-60% | Automated, runs 24/7, behavior-triggered | | Campaigns | 40-60% | Manual sends, promotional, content |

If your flows are generating less than 30% of your total email revenue, your automations are underbuilt. You're relying too much on manual campaigns, which means you're working harder for the same (or less) money.

If your flows are generating more than 70% of your total email revenue, you're probably not sending enough campaigns. Your list is just sitting there between automations, and you're missing opportunities to drive revenue with proactive sends.

The sweet spot for most brands is 50/50, give or take 10 points in either direction.

How to Check Your Split in Klaviyo

Go to Analytics, then Dashboard. Look at the revenue attribution for Flows vs. Campaigns. Klaviyo breaks this out for you. If you're heavily skewed one way, you know what to fix.

Also check: revenue per recipient for each flow. If your Abandoned Cart flow is generating $5 per recipient but your Welcome Series is generating $0.50, that tells you where to focus your optimization energy.

Campaign Frequency: How Much Is Too Much

The most common question I get about campaigns: "How often should I send?"

The answer depends on your brand, your list size, and your content. But here's the framework:

Minimum: 2 campaigns per week. If you're sending less than this, you're leaving money on the table. Your list is decaying while you're being "polite" about inbox space.

Sweet Spot: 3-4 campaigns per week. This is where most brands land after optimization. Enough to stay top-of-mind without burning the list.

Maximum: Daily (during sale events only). Outside of BFCM and major promotions, daily sends will spike unsubscribes unless your content game is genuinely exceptional.

The test: Watch your unsubscribe rate per campaign. If it's below 0.3%, you have room to send more. If it's above 0.5%, pull back or improve your content.

Flow Timing: Gaps That Cost You Money

The biggest flow mistake isn't building the wrong flow — it's having gaps between flows. Here's what I mean:

A customer buys from you. Your post-purchase flow sends 3 emails over 14 days. Then... nothing. For 60 days, until your winback flow triggers, that customer hears nothing from you except campaigns.

That 45-day gap between your post-purchase flow ending and your winback flow starting? That's where customers forget about you.

The fix: map your entire customer lifecycle and make sure there's a flow covering every stage. Welcome, post-purchase, replenishment, VIP acknowledgment, winback, sunset. No dead zones.

Building Your Decision Framework

Here's the framework we use at GOSH Digital. When a client asks "should this be a flow or a campaign?" we ask three questions:

Question 1: Is this triggered by something the customer did? Yes = Flow. No = Campaign.

Question 2: Should everyone on the list see this message, regardless of their recent behavior? Yes = Campaign. No = Flow (or segmented campaign).

Question 3: Would this message be weird if it arrived at a random time? Yes = Flow (timing matters, trigger it right). No = Campaign (timing is about your schedule, not their behavior).

If the answer to all three points to the same type, you're done. If there's conflict, you're probably in a gray area — and the answer might be "both."

The Setup Priority List

If you're starting from scratch or rebuilding, here's the order we'd build everything:

Week 1-2: Foundation Flows

1. Abandoned Cart (4-email sequence)
2. Welcome Series (3-5 emails)
3. Post-Purchase (4-6 emails)

Week 3-4: Revenue Flows 4. Browse Abandonment (2-3 emails) 5. Winback (3 emails) 6. Back in Stock (1-2 emails)

Week 5-6: Campaigns 7. Set up a weekly campaign cadence (2-3 per week) 8. Build 4-6 campaign templates for different purposes (promo, content, product, story) 9. Create your campaign calendar for the next 30 days

Week 7-8: Advanced Flows 10. Sunset flow 11. Replenishment flow 12. VIP flow 13. Birthday/Anniversary flow

By week 8, you have a complete email program. Flows handling the behavioral stuff on autopilot. Campaigns driving proactive revenue on your schedule. Both working together.

The Mistake That Costs the Most

Here it is, the single most expensive mistake I see in Klaviyo accounts: brands who use campaigns to do a flow's job.

They send a one-time "Hey, you left something in your cart" campaign to their abandoned cart segment every Tuesday. Instead of building an automated flow that fires within an hour of abandonment.

The campaign approach means customers who abandon on Wednesday don't hear from you until the following Tuesday. Six days of lost intent. Six days where they bought from someone else, forgot about you, or found a cheaper option.

A flow would have caught them within an hour. While the intent was still hot.

If you take nothing else from this post: automated behavioral responses should always be flows. Manual, scheduled messages should always be campaigns. Get that right, and you'll be ahead of 80% of Klaviyo users.

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