Last updated October 2026 by Lily Newman
An email campaign is a one-time send to a segment you choose, at a time you choose. A flow is an automated sequence set off by something a customer does (like joining your list or abandoning a checkout) or a time-based milestone (like a 60 day reactivation campaign). Platforms also call flows automations, triggers, journeys, or workflows. It’s all the same idea.
The numbers explain why flows get so much attention. In their 2026 benchmarks, Klaviyo, a leader in the marketing automation space for DTC brands, found that flows made up just 5.3% of email sends but nearly 41% of email revenue. That’s a huge gap. Not to mention that flows averaged a 5.58% click rate against 1.69% for campaigns (Klaviyo). This report is based on Klaviyo's customer base, so treat it as a strong signal for ecommerce rather than a universal law.
It is also easy to misread. Flow send volume is small because triggers are rare, not because campaigns are weak. A flow generally only emails people who did something (placed an order, subscribed to your list). Campaigns create the moments (a launch, a sale, a restock) that send people into your flows. Flows nurture and help provides the impetus for what happens next.
Campaigns and flows side by side
| Campaign | Flow | |
|---|---|---|
| Trigger | A date and time you pick | A customer action or date: signup, checkout started, order placed |
| Audience | A segment, chosen at send time | Whoever enters the trigger, continuously |
| Best for | Launches, sales, restocks, announcements, editorial | Welcome, abandonment, post-purchase, winback, renewals |
| Upkeep | A new build for every send | Build once, review quarterly |
| Main risk | List fatigue from over-sending | Stale copy, and offers that collide with campaigns |
| Judge it on | Revenue per recipient, click rate, unsubscribe rate | Revenue per recipient, placed order rate, conversion at each step |
Which flows to build first
If you have a campaign calendar and almost no flows, build in this order.
Welcome series. Someone just opted in and intent is high. The first thing to test is whether email #1 leads with an offer or with your brand story.
Abandoned checkout, then abandoned cart. People who started checking out are the warmest (highest intent) shoppers you have. Test the timing and content of the first email, but aim to hold any incentive for the second message so you are not discounting buyers who would have come back anyway.
Post-purchase. Confirm the customer's order, set expectations (aim to proactively answer what happens next), then ask for a review once the product has had time to land. Cross-sell by what’s relevant so the experience feels personalized, not by whatever you want to move.
Browse abandonment. Lower intent than checkout, so use a lighter touch. It also depends on reliable on-site tracking, so confirm that works before you invest.
Winback and sunset. Reach out to lapsed subscribers once or twice, then stop emailing the ones who fail to respond. Your deliverability depends on it, as my deliverability guide explains.
Replenishment. For consumables or subscription products, time a reminder to how long the product actually lasts. Better yet, make it dynamic based on individual consumption, frequency, and re-ordering behavior.
Subscription and membership brands should put onboarding, pre-renewal and cancellation-save flows near the top of the list. That is where retention math lives.
Where campaigns and flows collide
Put both on one calendar. The quickest way to waste a flow is a promotional campaign landing an hour after an abandoned checkout email. Most platforms have a setting that skips recipients who just received a message (Klaviyo calls it “Smart Sending”), so check how it treats flow emails before you rely on it. Then set a rule: someone who just received a flow email does not get a same-day promo unless the promo is the point. Use segmentation to thoughtfully include or exclude subscribers as needed.
SMS follows the same logic. Use it for the moments with a clock on them, and keep it out of flows that email already handles, as my SMS guide covers.
How to measure each one
Skip open rate. Apple Mail Privacy Protection inflates it, so it no longer tells you something actionable or accurate. Instead, I recommend comparing campaigns and flows on revenue per recipient, click rate and placed order rate, and watch the unsubscribe rate on both.
Frequently asked questions
What is the difference between an email campaign and an automation? A campaign is a one-time send you schedule to a segment. An automation, or flow, sends automatically whenever a customer triggers it.
Do flows replace campaigns? No. Campaigns drive the demand that feeds your flows, and flows convert it. You need both.
Which flow should I build first? The welcome series, then abandoned checkout, then post-purchase.
How often should I update a flow? Review copy, offers and performance every quarter, and sooner when your promotional calendar changes.
Should a restock be a campaign or a flow? A flow for people who asked to be notified, and a campaign for everyone else.
Not sure which flows your program is missing? Newly Marketing audits lifecycle programs and builds the gaps.
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About the Author
Lily Newman is the Founder and Principal of Newly Marketing, a digital marketing consultancy specializing in lifecycle, email, mobile, CRM, and retention marketing. A fractional DTC e-commerce marketing leader, Lily advises high-growth startups and Fortune 500 brands in retail, CPG, health and wellness, and technology, drawing on 15+ years leading acquisition and retention for Levi's, Peet's Coffee, Mighty Leaf Tea, Four Sigmatic Foods, and more.
