- Amazon says sellers can contact buyers only to complete an order or answer a customer service question. Marketing and promotional messages aren't allowed.
- Your email list has to come from places you own: your Shopify store, your pop-up, your social channels, retail and events.
- For brands on both channels, email's real job is making the second DTC order automatic, so a reorder doesn't drift to Amazon by default.
- Inserts in your own Shopify boxes are fair game. Inserts in Amazon orders are a different story. Check Amazon's current rules before you print anything.
Can I email my Amazon customers?
Not for marketing. An Amazon staff member on Amazon's Seller Forums summed up the Communication Guidelines this way: "In general, you can contact buyers only to complete orders or to respond to customer service questions." The same post says plainly, "You cannot contact buyers for marketing or promotional purposes."
Permitted messages are about getting the order done: sorting out a fulfillment problem, sending an invoice, requesting a review or seller feedback, or anything else that's needed for the buyer to receive their purchase. The post also warns that breaking the rules can get your proactive messages limited to Amazon's templates or your selling privileges suspended.
So if your plan was "export Amazon buyers, upload to Klaviyo, send a welcome flow," don't. That's not a gray area. Amazon's rules on this change from time to time, so read the current Communication Guidelines in Seller Central before you do anything with buyer contact info.
What can email actually do for a brand on both channels?
More than people think. It just works on a different group of people.
Amazon is great at catching people who are already searching. Your email list is where you build a relationship Amazon won't let you have. The job splits into three parts:
- Build a list on channels you own. Your Shopify site, your sign-up forms, social, retail sampling, events.
- Make the second DTC order automatic. Post-purchase, reorder reminders and winback, so someone who bought on your site has a reason to come back to your site.
- Tell your list what's going on. Launches, restocks, retail wins. These are the sends that make a list feel like it's worth being on.
Ads are rented, your list is owned. Amazon is rented too. The list is the part you keep if the rules, the fees or the algorithm change.
How do I keep repeat purchases from drifting to Amazon?
Here's the thing with consumables. When someone runs out, they reorder wherever it's easiest. If you don't show up at the right moment, the easiest place is often the Amazon app already on their phone.
That's why the reorder reminder matters so much for these brands. Across four consumable brands in my data, replenishment flows earned about $2.23 per person, about 28x the best campaign. Only 2 of the 4 brands had one built. It's not one of the 8 core flows in my Flow System. It's the one I'd add on top of them first for anything that runs out.
Here's where I'd start:
- Time the reminder to when they run out. Base it on how long the product lasts, not a round number. My replenishment email timing post covers how.
- Make reordering on your site the easy option. One click back to the product, the right size and flavor already picked.
- Give a reason to stay direct. Bundles, subscribe-and-save, early access to new flavors, free shipping thresholds. Pick what fits your margins. You don't need to undercut Amazon on every SKU.
A subscription wellness brand I work with got $47,321 in one month from a single "your order is coming up" reminder, 74% of all its flow revenue. That's the kind of email that keeps the reorder on your site.
What about package inserts?
Two different situations.
In your own Shopify orders, inserts are yours to use. A card with a QR code to a reorder page, a "join the list for early access" offer, a note about how long the product lasts and when to reorder. It's a nudge toward the next order in the hands of someone who already bought.
In Amazon orders, be careful. Amazon has its own rules about what can go in the box, and sellers on Amazon's own forums disagree about what's allowed. The safe rule: don't use an Amazon package to pull a buyer off Amazon. Before you print anything for Amazon orders, check the current policy in Seller Central or ask Seller Support.
Should I send my email list to Amazon?
Sometimes, on purpose. A launch where the product is only on Amazon at first, or a retail-style push where you want reviews and rank on a new listing, can be a reason to point some sends there.
Just know what you're giving up. Someone who buys on Amazon becomes Amazon's customer in a way someone who buys on your site doesn't. And in a standard Shopify plus Klaviyo setup, Klaviyo's revenue numbers come from Shopify orders, so sales that happen on Amazon from an email click won't show up as email revenue.
My default is to send your list to your own site. If you send to Amazon, do it for a specific reason and judge it by clicks, since your Klaviyo revenue numbers won't tell the full story.
How do I grow a list when most of my sales are on Amazon?
Your list grows from your owned traffic, not your Amazon traffic. If most of your sales are on Amazon, that list will grow slower, and that's OK. A smaller list of people who chose your site is still worth more to you than a bigger one you can't legally market to.
Start with a sign-up form on your site that gives people a real reason to join. Then make sure every new subscriber lands in a welcome flow. In the Flow System I install, the welcome series is 6 emails over 7 days, and the offer goes in email #1 because it carries most of the money: about $4.50 per person in my four-brand data, about 30x what emails #2 to #5 earned. The rest of the week builds trust before the offer expires. For more, see how to grow an email list.
Where these numbers come from
The welcome and replenishment numbers are pooled from 4 consumable brands I work with: 2,897 campaigns and $17.7M in email revenue. It's a small sample, so read it as directional. The subscription reminder number is from one client account. Amazon's rules are quoted from Amazon's own Seller Forums, linked in Sources.
FAQ
Can I add Amazon buyers to my Klaviyo list?
Not for marketing. Amazon's Communication Guidelines limit seller contact to completing orders and customer service questions, and marketing or promotional messages aren't allowed. Build your list from your own site and channels instead.
Can I ask Amazon buyers for a review?
Requesting a product review or seller feedback is listed as a permitted message, through Amazon's messaging. Keep it to the request itself and follow Amazon's current guidelines on wording.
Is email marketing worth it if most of my sales are on Amazon?
Yes, if you sell something people reorder. Even a small DTC base can carry real revenue once a reorder reminder and winback are running. Just set expectations: the list grows from your own traffic, so it'll be smaller.
Should my DTC prices match Amazon?
That's a business call bigger than email. What email can do is give people a reason to buy direct that isn't only price, like bundles, subscriptions, early access or a free shipping threshold.
Which Klaviyo flows matter most for brands on both channels?
Welcome and the abandonment flows to turn site visitors into first-time buyers, then post-purchase, a reorder reminder and winback to keep them buying on your site. Here's the full setup in the essential Klaviyo flows for CPG brands.
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.