Flows first. Campaigns second.
The single most useful thing to understand about Klaviyo: the money is in the flows, not the newsletters. Flows run automatically, forever, triggered by what someone did. Campaigns are a one-off send that you have to keep producing.
So if an agency's first-month plan is a content calendar of weekly newsletters, they have started at the expensive end. The flows get built once and keep earning while you sleep, Klaviyo's own documentation is built around exactly this distinction.
The flows that actually earn
- Abandoned cart. The obvious one, and still the biggest. Baymard puts average cart abandonment near 70%, a meaningful slice of that is recoverable with a well-timed, non-desperate reminder.
- Browse abandonment. Someone looked and left. Lighter touch, still worth real money.
- Welcome series. Highest engagement you will ever get from a subscriber. Do not waste it on a 10% discount and silence.
- Post-purchase. The cheapest revenue in e-commerce is the second order from someone who already trusts you.
- Win-back. Cheaper than acquiring a stranger, and most stores never build it.
Build those five properly and most stores are capturing the large majority of what email can do for them. Everything after that is refinement.
What a good Klaviyo agency actually does
- Fixes the data first. Klaviyo is only as good as the events flowing into it. If the integration is half-configured, the segmentation is fiction.
- Segments by behavior, not demographics. What people did beats who they are, every time.
- Writes emails a human would read. Plain, useful, not a wall of discount codes.
- Watches deliverability. Sending more to people who never open is how you end up in spam and take your good subscribers with you.
- Reports revenue, not opens. Open rates have been unreliable for years. Revenue per recipient is the number.
That last one matters. Data you do not act on is just expensive decoration, and open rates are the most decorative metric in email. If the monthly report leads with them, ask what happened to the revenue.
When you should not hire a Klaviyo agency
- Your list is tiny. Email is a leverage channel, it multiplies an audience you already have. With a few hundred contacts, build the audience first.
- The five core flows are already live and working. Then you may need a few hours a month, not a retainer.
- Your product has no repeat purchase and no considered decision. Email needs a reason to follow up.
- Your store cannot convert its existing traffic. Fix that first, email will just deliver more people to the same leak.
When the list is real and the flows are missing, though, this is some of the highest-return work in marketing: you are talking to people who already raised their hand. That is what our email marketing work focuses on, and it is deliberately built around flows before campaigns.
Deliverability: the problem nobody notices until it is bad
You can have perfect flows, sharp copy and beautiful design, and still quietly end up in spam. When that happens, nothing in your reporting screams. The revenue just drifts down and everyone blames the creative.
Deliverability is mostly a consequence of who you send to, not what you send. Mailbox providers watch engagement. If you keep emailing people who never open, they conclude your mail is unwanted, and then they start filtering the mail your good subscribers would have read.
- Sunset the dead weight. People who have not engaged in months are not an audience. They are a liability, and removing them usually improves revenue because your good subscribers start reaching the inbox again.
- Never buy a list. Ever. It is a fast route to poisoning a sending reputation that takes months to rebuild.
- Warm up gradually. Going from zero to a hundred thousand sends overnight is the single most reliable way to look like a spammer.
- Watch the technical setup. Authentication and sending domains matter, and Klaviyo's documentation walks through the configuration properly.
The counterintuitive part, and the one clients resist hardest: sending to fewer people usually makes you more money. A smaller, engaged list beats a large, indifferent one, because the large one is actively damaging your ability to reach the people who actually want to hear from you.
If an agency has never mentioned list hygiene, ask why. It is the least glamorous conversation in email and one of the most valuable.
Frequently asked questions
What should a Klaviyo agency build first?
Flows, not newsletters. The five that earn most are abandoned cart, browse abandonment, welcome series, post-purchase and win-back. They are built once and keep running; campaigns have to be produced again every week. An agency leading with a content calendar has started at the expensive end.
Which Klaviyo flow makes the most money?
Abandoned cart, almost always. Average cart abandonment sits around 70%, and a well-timed reminder recovers a meaningful share of it. Post-purchase is the quiet runner-up, because a second order from an existing customer is the cheapest revenue in e-commerce.
Should I judge email marketing on open rates?
No. Open rates have been unreliable for years thanks to privacy changes and image proxying. Judge on revenue per recipient and revenue per flow. If an agency report leads with opens, ask what happened to the money.
When do I not need a Klaviyo agency?
When your list is very small, email multiplies an existing audience rather than creating one, or when your five core flows are already live and performing. In the second case, you may need a few hours a month of maintenance, not a full retainer.