Which flows to build first, what happens when one subscriber qualifies for two at once, and how to tell which flow is earning.
- Build abandoned checkout, welcome, post-purchase, and browse abandonment first, in that order, then add winback, replenishment, and sunset.
- Klaviyo evaluates every flow independently, so one subscriber can be in two flows at once unless your filters decide which one wins.
- Set a flow hierarchy and enforce it with profile filters, and add Placed Order zero times since starting this flow to every flow that sells.
- Smart Sending skips emails rather than delaying them, so turn it off on the first email of your welcome and abandoned checkout flows.
- Compare flows on revenue per recipient, check Klaviyo's numbers against Shopify each month, and run a holdout on your largest flow.
On this page
Flows are the emails Klaviyo sends on its own when a shopper does something: subscribes, browses, starts a checkout, buys, or goes quiet. Campaigns go out when you press send. Flows keep sending whether anyone is at a desk, which makes them the first place to look when email revenue is lower than it should be.
This guide covers which flows to build first, what happens when one subscriber qualifies for two flows at once, and how to tell which flow is earning.
Build these four first
For a Shopify store doing $1M to $5M a year, four flows cover the moments with the most intent. Build them in this order, and get each one live with its filters before you start the next.
- Abandoned checkout. It is triggered by Checkout Started. These shoppers chose a product and typed their email, so this flow usually earns the most per person who receives it.
- Welcome series. It is triggered when someone joins your email list. New subscribers know the least about you, and many are deciding on a first order, so this flow sets the tone for everything after.
- Post-purchase. It is triggered by Placed Order. It thanks the customer, sets delivery expectations, and shows how to use the product. Use a conditional split to send first-time buyers and repeat buyers different messages.
- Browse abandonment. It is triggered by Viewed Product and reaches shoppers who looked at a product and left. It needs Klaviyo onsite tracking and only fires for shoppers Klaviyo has already identified.
The next three
Once those four are live and filtered, add these.
- Winback reaches customers who have not ordered in longer than your usual repeat cycle. Set the delay from your own order data. If most second orders happen within 60 days, a winback at 90 to 120 days is a reasonable starting point.
- Replenishment fits products that run out on a predictable schedule. Time each message to the product's usage, not to a calendar date.
- Sunset stops emailing subscribers who have not clicked in a long stretch, often 90 to 180 days. It protects deliverability, meaning whether your emails land in the inbox instead of spam.
What happens when one subscriber qualifies for two flows
Klaviyo evaluates each flow on its own. A new subscriber who starts a checkout ten minutes after signing up enters your welcome series and your abandoned checkout flow at the same time. Without filters, they receive both.
Three settings decide what that person sees: profile filters, Smart Sending, and the timing of each flow.
Profile filters
Profile filters are conditions Klaviyo checks when someone enters a flow and again before every email. If a profile stops matching, Klaviyo skips that email. For filters like Placed Order zero times since starting this flow, it keeps skipping every email after that. They are the main tool for deciding which flow wins.
The pattern is a hierarchy. Decide which flow takes priority, then filter the lower-priority flow so anyone who enters the higher one stops receiving it. A common order, highest first, is abandoned checkout, then welcome, then browse abandonment, then winback.
- In browse abandonment, add Checkout Started zero times since starting this flow, so a shopper who reaches checkout moves to the checkout flow.
- Klaviyo has no built-in filter for whether someone is currently in another flow. A simple stand-in is to filter browse abandonment with Subscribed to List zero times in the last 9 days, which matches a nine-day welcome series.
- In every flow that sells, add Placed Order zero times since starting this flow, so a purchase ends the sequence.
Whether welcome should yield to abandoned checkout is a judgment call. If your welcome series carries a first-order code, one option is to let the subscriber stay in both, since the reminder and the code support each other. If it does not, adding Checkout Started zero times since starting this flow to the welcome series keeps the inbox quieter.
Smart Sending
Smart Sending skips a message if the profile received another email from you within a set window, 16 hours by default. You change the window under Settings > Email > Sending preferences. It applies across flows and campaigns.
It skips the email outright rather than queueing it for later. A time-sensitive email can disappear without anyone noticing, so turn Smart Sending off on the first welcome email and the first abandoned checkout reminder. Leave it on everywhere else.
Flow timing
The delays decide which email lands first. If your first checkout reminder sends at four hours and your second welcome email sends at one day, the two rarely collide.
Map the first three days of each flow on one sheet. Look for any day where a single subscriber would get three emails, and adjust the delays or the filters until that day is gone.
How to tell which flow is earning
Klaviyo's flow analytics show revenue for each flow and each email. That number is a starting point, and three habits make it useful.
Compare on revenue per recipient
Total revenue favors flows with large audiences. Revenue per recipient, the attributed revenue divided by the number of people who received the flow, lets you compare a winback against an abandoned checkout on equal terms.
Look at it per email as well. If the third email in a flow earns a small fraction of the first, test removing it.
Remember that every platform claims the same order
Klaviyo credits the last email a shopper opened or clicked before buying. The purchase has to fall inside the attribution window, meaning the period after an email during which a purchase counts toward it, five days by default. Meta and Google run their own windows. One order often appears in Klaviyo, Meta Ads Manager, and GA4 at once, so the platform totals add up to more than your Shopify revenue.
In Klaviyo's attribution settings, remove Apple Privacy Protection opens from attribution, since Apple Mail opens emails automatically. Then check flow revenue against Shopify each month rather than reading it on its own.
Run a holdout on your largest flow
The clearest way to measure a flow is to withhold it from a random group and compare. Add a conditional split at the top of the flow using the random sample condition. Send most profiles through the emails and a small share, often 10 percent, down a branch with no emails.
Tag each branch with a profile property so you can build a segment for each group. After a few weeks of volume, compare placed order rate between the two segments. The difference is what the flow adds beyond what those shoppers would have done anyway.
Our email revenue gap tool gives you a rough estimate of what flows should contribute at your size, which is a useful number to hold your analytics against.
What to do this week
Open Flows in Klaviyo and list every live flow with its trigger and its filters. Mark which of the four core flows are missing, and which live flows have no Placed Order filter.
Then pick one recent subscriber and trace their profile. Check which flows they entered and what they received in their first three days, using the activity history on their profile.
If that person received more than four emails in three days, fix the filters before you build anything new.
If you want an outside view first, the free growth plan is a six-month plan we build for your store from the outside, with no logins, and walk you through on a call. Building and running flows is part of our email and SMS work. The first flow to rebuild is usually abandoned checkout, and Build a Klaviyo Abandoned Cart Flow covers it step by step.
