Definition
An email flow is a multi-step automated email sequence triggered by a specific subscriber event, action, or condition. The term "flow" is most closely associated with Klaviyo, which distinguishes flows from campaigns as its primary sending paradigm, but the concept exists across virtually all modern email marketing platforms under names such as journeys, automations, or workflows. A flow consists of three elements: a trigger (what starts the flow), filters (who enters the flow), and actions (what happens, including email sends, delays, splits, and conditional branches).
Common flow types include welcome series (triggered by subscription), browse abandonment (product page views without purchase), cart recovery (add-to-cart without checkout), post-purchase follow-up (order placement), and winback sequences (prolonged inactivity). Each maps to a specific lifecycle stage and uses different success metrics. Welcome flows are measured by activation rate and first-purchase conversion; winback flows are measured by re-engagement rate and churn reduction.
In Klaviyo's architecture, campaigns are single sends to a chosen segment at a chosen time, while flows are event-driven, always-on sequences that execute independently for each subscriber. Klaviyo's benchmark data shows flows consistently outperform campaigns, with welcome flows generating 5x more revenue per recipient than broadcast campaigns in many ecommerce verticals.
Best Practices
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Design flows with a single, measurable objective per sequence. A welcome flow should drive first-purchase conversion, not also attempt cross-sells and upsells. Keep the focus narrow and measure the flow against that primary goal.
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Use flow filters to prevent subscribers from entering the wrong sequence or overlapping with contradictory flows. For example, a browse abandonment flow should check that the subscriber has not already purchased the viewed item and is not currently active in a cart recovery flow.
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Implement delay steps strategically. The first email in a welcome flow sent immediately after sign-up performs well, but subsequent emails should space out at intervals of 24–72 hours to avoid overwhelming new subscribers.
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Add conditional splits based on engagement behaviour. If a subscriber clicks a link in email two of a five-step flow, consider skipping to the conversion-oriented final email rather than sending the remaining intermediate messages.
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Monitor flow-level analytics including completion rate, conversion rate, revenue per recipient, and time-to-conversion. Use these metrics to identify drop-off points where subscribers exit the flow or stop engaging.
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A/B test flow architecture changes incrementally. Test single variables such as trigger timing, email count, or subject lines before restructuring an entire sequence. Flow tests accumulate data rapidly because triggered sends occur continuously.
Related Glossary Terms
Email Automation Campaign
A pre-set sequence of emails triggered by subscriber actions or conditions, running continuously without manual intervention.
Email Bulk vs Triggered
The distinction between broadcast campaigns sent to large segments simultaneously and triggered messages sent in response to individual subscriber actions or events.
Email Customer Retention
Email customer retention strategies use targeted campaigns, predictive churn models, and automated retention workflows to reduce churn and increase repeat purchase behaviour.
Email Engagement Tier
Email engagement tiering categorises subscribers into levels such as engaged, warming, passive, at-risk, dormant, and dead. Tier transition triggers enable automated send frequency and content strategy adjustments.
Email Floodgate Protection
Safety mechanisms that prevent automated email triggers from sending excessive volumes during event surges or configuration errors.
Email Lifecycle Email
Lifecycle email campaigns mapped to subscriber journey stages including trigger configuration, performance analysis, and content strategy for each stage.
Frequently Asked Questions
A campaign is a one-time or recurring send to a selected segment at a scheduled time. A flow is an automated, event-triggered sequence that runs continuously and independently for each subscriber. Flows respond to behaviour; campaigns respond to a calendar.
Use flows for repetitive, behaviour-driven communication such as welcome series, cart recovery, and post-purchase follow-up. Use campaigns for time-sensitive announcements, newsletters, product launches, and seasonal promotions that target a defined audience at a specific moment.
Yes. A subscriber can be active in several flows simultaneously. For example, a new subscriber might be in both a welcome flow and a birthday flow. Use flow filters and priority rules to manage overlap and prevent contradictory messaging.
Review every flow at least quarterly. Check that trigger conditions still align with current site behaviour, that offers and copy remain relevant, and that flow metrics meet performance targets. Retire flows that no longer drive meaningful engagement.
The most important flow metrics are conversion rate (percentage of entered subscribers who complete the desired action), revenue per recipient, flow completion rate, and time-to-conversion. Secondary metrics include open rate, click-through rate, and unsubscribe rate within each step.