Klaviyo flows that pay the rent

Retention is half the equation — and the cheapest half

Most brands massively over-invest in acquisition and under-invest in what happens after a customer's first purchase. But CLTV is built after the first order, and every euro CLTV rises is another euro you can afford to spend winning the next customer. Retention isn't an appendage to performance marketing. It's the other half of the equation that decides how hard you can scale acquisition.

Klaviyo is where that half is won, because flows are automated: built once, they run in the background and produce contribution margin without a single extra ad euro. It's the most profitable traffic you have. For a well-run account, email and SMS often account for a meaningful double-digit share of total revenue, driven mostly by flows, not by campaign broadcasts.

The flows that carry the revenue

The welcome flow converts the curiosity a new subscriber arrives with, while interest is hottest, and sets the tone for the relationship. Abandoned checkout and abandoned cart catch the ones who came closest to buying, and browse abandonment reaches those who showed interest without adding to cart.

The post-purchase flow is underrated: it triggers the second purchase sooner and thereby shortens the payback period directly, while reducing returns and support load through good product onboarding. Replenishment flows (for consumables) hit when the item is about to run out, and winback and reactivation flows bring dormant customers back before they're lost for good.

Together, it's these six or seven flows that carry most of the automated revenue. The most important ones to build first: welcome, abandoned checkout, browse abandonment, post-purchase and winback.

Flow anatomy: a flow is decision logic, not an email

The difference between a flow that makes money and one that annoys lies in the logic. A flow starts with a trigger (e.g. "added to cart" or "placed order"), and from there we build conditional branching: if the customer has already bought, the reminder shouldn't send. If it's a VIP, the tone and the offer should differ from what a first-time visitor gets.

Time delays control the timing (wait 1 hour, then 22 hours, then a final nudge), conditional splits route the customer down the right branch, and trigger splits can send high-value carts one way and low-value carts another. A/B splits on subject lines and content sharpen the flow over time, and smart sending prevents the same customer from being bombarded with messages from several flows in one day.

A discount is not the default. Build the first steps without a discount and let only the most price-sensitive reach an offer at the last step — otherwise you teach customers to wait for the discount code and erode your margin.

Segmentation & data: talk to the customer, not the list

The power lies in segmentation. An RFM approach (recency, frequency, monetary) splits the base by when they last bought, how often, and for how much — letting you speak to first-time buyers, repeat customers, VIPs and dormant customers each in their own way. A campaign to "everyone" is almost always worse than three targeted ones.

Klaviyo's predictive analytics estimates expected CLV, likely next-order date and churn risk at the profile level. That lets you, for instance, trigger a winback before a customer is statistically about to lapse, instead of after. And because Klaviyo can talk to the rest of the setup, the same customer data that drives segmentation can also feed the ad channels: a summer campaign doesn't have to start from zero every year, but can build on who bought last season.

Set up right, acquisition and retention become one system instead of two silos. The same profit and customer data make both the ads and the email sharper.

Deliverability: all of the above depends on the email arriving

The best flow logic is meaningless if the email lands in spam. Deliverability is governed by your sender reputation, which is built over time through engagement — opens, clicks, purchases — and destroyed by sending to unengaged or dead addresses.

That's why a sunset flow isn't optional: profiles that haven't engaged in, say, 90-120 days are stepped down and eventually out of active sending. It feels counterintuitive to stop emailing people, but it protects your reputation so the engaged ones actually receive your messages. Combined with proper domain authentication (SPF, DKIM, DMARC), a dedicated sending subdomain and ongoing list hygiene, it's the difference between a list that makes money and one that slowly disappears from the inbox.