A campaign goes out to a list on a date you choose. A flow fires because somebody did something: browsed, added to cart, bought, or stopped buying. The difference matters because flows compound and campaigns do not. A flow you build once keeps earning while you sleep, and a campaign earns once.
On Curated Chrome, the brand we owned and ran for seventeen months, 72.7% of email revenue came from flows. That number is the diagnostic. If yours is far below it, you are almost certainly sending a lot of email and capturing very little of the automatic revenue sitting underneath it.
The flows that carry the money
Most of the revenue in a healthy programme sits in a small number of sequences, and they are the boring ones. Welcome, for people who signed up but have not bought. Abandoned cart, for people who got as far as intent. Browse abandonment, for people who looked and left. Post purchase, which is where the second order is made or lost. Winback, for people who used to buy and stopped.
That is the list. Everything else is a refinement. A store with those five running properly and no campaign calendar at all will usually out earn a store with a beautiful weekly newsletter and two half configured flows.
A flow built once keeps earning. A campaign earns on the day you send it and then stops.
What campaigns are actually for
Campaigns are for the things a flow cannot know: a launch, a genuine deadline, a restock, a point of view. They also keep the list warm, which matters for deliverability. What they are not for is carrying the revenue. A programme that leans on campaigns is a programme that has to send more email every month to stand still, and the list gets tired faster than the numbers show.
How to read your own split in ten minutes
Open the Klaviyo revenue report, set it to the last ninety days, and split attributed revenue between flows and campaigns. Then do the honest correction: compare the total that Klaviyo claims against what the store actually took in the same window, because email attribution windows are generous and the platform counts a purchase it touched as a purchase it caused. The ratio between flows and campaigns survives that correction even when the absolute number does not, which is why the ratio is the better diagnostic.
The mistake that costs the most
Building flows once and never reading them again. A welcome sequence written for a catalogue you no longer sell, an abandoned cart email pointing at a discount you have stopped honouring, a post purchase flow that recommends the item the person just bought. These decay silently, because nothing in the platform tells you a flow has gone stale. Read every live flow end to end twice a year, as a customer would receive it.
What we do with it
We check the flow to campaign split before touching the sending calendar, then we read every live flow as a customer receives it, and only then do we talk about what to send this week. The full case is on the Curated Chrome page, and the channel is on the email page.