- I build cross-sells as standalone flows, used in post-purchase or customer winback contexts. Overlap with your other post-purchase emails isn't a problem.
- My default is a specific version of the flow for each product. One layout and setup, duplicated for each item.
- Pick pairs based on the brand: a product that complements the hero item, an accessory, or another flavor. Then time it to how that product gets used.
- Accessories can wait longer after the purchase. Restock products shouldn't ask for another purchase too soon.
This is for Shopify founders selling food, drinks, supplements, skincare or anything else people use up, who have a pile of one-product buyers and want more of them trying product two.
Why build the cross-sell as its own flow?
Because it has one job, and that job is easier to manage on its own. A cross-sell flow says: you bought A, here's B. When it lives in its own flow, you can set its trigger, its timing and its exclusions without touching the emails that thank people, teach them how to use the product, or remind them to reorder.
I use cross-sell flows in two places:
- Post-purchase. Someone just bought, they're paying attention, and you know exactly what they ordered.
- Customer winback. Someone bought before and went quiet. A different product can be a better reason to come back than the same one again.
A common worry is overlap: won't this person also be getting the regular post-purchase emails? Yes, and that's fine. Overlap with the other post-purchase emails isn't a problem in the accounts I build. The cross-sell is about a different product, and it lands on its own schedule. I walk through the rest of the post-purchase setup in what a post purchase email flow should send.
Should you build one flow per product or one general flow?
You have two options, and I'll give you both.
Option 1: a specific flow for each product (my default). It's easier to build specific versions of the flow for specific products than to rely on dynamic sections. Once one layout and setup works, you duplicate it and repeat it for each item. The buyer of product A gets an email about product B, written for that exact pair. The copy can say why B goes with A, because you know they own A.
Option 2: one general cross-sell flow. This one gets more sends in one series, because every buyer goes through it. The upside is learning: it helps you see which products people buy most from it at a given point in the customer life cycle. If you're not sure what your natural pairs are yet, a general flow can show you.
Start with option 1 for your hero product. If you're guessing at pairs for everything else, a general flow is a reasonable way to find out what people actually reach for.
How do you pick the second product?
I pick pairs based on the brand. There's no universal rule, because a snack brand, a skincare brand and a supplement brand all have different "next" products. Here's how I think about it:
- A complement to the hero item. When a brand has products that complement its hero item, I build a flow that recommends that item to hero buyers.
- An accessory. Something that makes the main product easier or better to use.
- Another flavor, scent or variety. For consumables, this is often the easiest yes. The first order proves someone likes the product. A second flavor proves they like the brand.
The question to ask for each one: what makes sense next in this customer's life cycle? Not what has the most inventory, and not what you'd like to move this month.
When should the cross-sell email go out?
This depends on what you're recommending, and it's where most of the thought goes.
Accessories: later. For accessories, I schedule the recommendation later after the purchase, so we're not hounding the customer. Let them use the main product first. An accessory pitch the day after the order feels like a checkout upsell that followed them home.
Restock products: not too soon. If the second product is something they'll use up, like another flavor, avoid asking for another purchase before they've had a real chance to get through the first order. Asking someone to buy more when the first bag is still half full is how you train people to ignore you.
A pattern worth knowing. One thing our data showed: at the 30 to 40 day mark, the post-purchase thank-you email earned much higher revenue per recipient than the customer winback. The likely reason is that customers are ready to restock sooner than the winback assumes. So for consumables, the window right around a month after the order is a good place to be in front of people, whether you're pointing them at the same product or a new one.
If you're not sure when your customers run out, look at how long they actually wait between orders. I cover how I work that out in replenishment email timing.
How do you set up a cross sell email flow in Klaviyo?
For a specific per-product flow, the build is simple.
- Trigger on the order. Use Placed Order as the trigger. Per Klaviyo, trigger filters look at the data in the event that starts the flow, so you can narrow a Placed Order flow to orders that contain a certain product or category. Point it at product A.
- Keep out people who already own product B. Klaviyo's help center shows a cross-sell segment built on two conditions: Ordered Product at least once over all time where the SKU is product A, and Ordered Product zero times over all time where the SKU is product B. Use the "zero times" condition for product B as a profile filter on the flow. Per Klaviyo, profile filters are checked when someone enters a flow and again before each email, so anyone who buys B partway through skips the rest.
- Set the delay for the product. Short-ish for a complement, longer for an accessory, and not before they'd realistically need more for a restock product.
- Write it for the pair. Say why B goes with A. You know what they bought, so use it.
- Duplicate it. Once it works, clone the flow for the next pair and swap the trigger filter, the profile filter and the copy.
Before you build, check that Ordered Product events are syncing from Shopify with the SKU or name you plan to filter on. Klaviyo's cross-sell article calls that out as the first step. And if you build the segment for campaigns too, add the "can receive email marketing" condition, since the purchase conditions alone don't limit it to subscribers.
Can the reorder reminder mention a second product?
Yes. I'm fine adding a line like "add a second flavor to this order" inside the reorder reminder.
Keep it a line, not the headline. The reorder email's main job is getting them more of what they already love, and that email is worth protecting. Across 4 consumable brands I work with, replenishment flows earned about $2.23 per person, about 28x the best campaign, and only 2 of the 4 brands had one built. A small add-on line rides along with that without getting in its way.
What does this look like for a food brand?
Food is the easiest place to see it. Here's how I'd set it up for a snack brand with a hero flavor and a few others:
- A per-product cross-sell flow for hero flavor buyers, recommending the flavor that pairs best with it.
- A delay that gives them time to get through some of the first order before the ask, since flavors are restock products.
- A profile filter so anyone who already bought the second flavor never gets the email.
- An "add a second flavor to this order" line in the reorder reminder.
- The same flow, duplicated, for buyers of your second-best seller.
There's more on food brands in email marketing for food brands, and the bigger picture of getting the second and third order is in my repeat purchase email strategy.
Where these numbers come from
The $2.23 per person figure comes from 4 consumable brands I work with: 2,897 campaigns and $17.7M in email revenue. It's a small sample, so treat it as directional. On the outside research: an Experian CheetahMail report from 2010, which looked at more than 1,800 order, shipping and return confirmation emails, found that transactional emails with cross-sell items had 20% higher transaction rates than those without. It's old and it's about confirmation emails, not a full flow, but it points the same way.
FAQ
What is a cross sell email?
It's an email that recommends a different product to someone based on what they already bought. For a consumable brand, that's usually a complementary product, an accessory or another flavor.
Should a cross sell email flow be separate from the post-purchase flow?
I build it as its own flow and use it in post-purchase or customer winback contexts. The overlap with your other post-purchase emails isn't a problem, and keeping it separate makes the timing and exclusions easier to control.
How many products should a cross-sell email show?
One clear pick. A per-product flow works because it's about one specific pair. If you want to test a wider range, that's what a general cross-sell flow is for.
Should the cross-sell email include a discount?
It doesn't need one by default. A product that clearly fits what they already bought is the reason to buy. I cover when offers help and when they hurt in email discount strategy.
How do I know if my cross-sell flow is working?
Look at clicks and at how many people who got the flow went on to order the recommended product. Opens are inflated by Apple and Google, so don't judge it on opens.
Founder of Bardown Digital, a Chicago-based Klaviyo email and retention agency for Shopify brands. He's worked with brands doing $500K to $100M a year, with $100M+ in email-attributed revenue across them.