Ecommerce Email Marketing: Which Flows First, What They Add

Start with emails that react to what a shopper does, and add newsletters later. First come abandoned cart and browse emails, then a welcome series, then post-purchase, back-in-stock and win-back emails. Authenticate your sending domain before the first send. The email tool’s revenue figure also counts orders your ads brought. To see whether a flow adds orders, hold back the message from a random part of its audience. Then compare orders in your shop’s own records. The same check applies to SMS.

Email is one part of a wider job: bringing buyers back to an online store. This guide covers the email and SMS side of it in short answers, with a detailed article for each part. It assumes your new customers come mostly from Google Ads. So every section asks one extra question: what does this message add to the orders you already pay for?

Which emails should a store running Google Ads set up first?

Start with automated flows, then add campaigns. An email flow is a series of emails that starts by itself when a shopper does something: signs up, leaves a cart, places a first order. A campaign is a one-off send to a list, such as a sale or a newsletter.

Example store, not client data.

A tableware shop gets 8,000 clicks a month from Google Ads and 300 orders. That is a conversion rate of 3.75%, so 7,700 paid clicks a month end without an order. Some of those visitors leave an email address or start checkout. A flow reaches them again without another paid click.

Set them up in this order:

1. Abandoned cart and browse emails. An abandoned cart email goes to a shopper who added a product and left. A browse email goes to one who viewed a product and added nothing. Both reach visitors you have already paid for, within hours of their visit.
2. Welcome series. It greets new subscribers and turns a signup from a paid visit into a first order.
3. Post-purchase emails. They thank the buyer, explain delivery and use, then suggest the next product.
4. Back-in-stock and price-drop alerts. They turn a sold-out page into a waiting list instead of a lost visit.
5. Win-back emails. A win-back campaign goes to customers who have stopped buying. It becomes worth setting up once you have enough past buyers to lose.
6. New-arrivals campaigns. A regular send shows your newest products to people who already know the shop.

Order confirmations and shipping updates come from your shop platform and usually already exist. Keep promotions out of them. Gmail’s sender guidelines ask senders to keep content types apart, for example to keep promotions out of sales receipts.

Abandoned cart and browse: the closest flow to your ads

This flow follows the ad click within hours, so it overlaps with your ads more than any other flow. Abandoned cart and browse emails covers how many messages to send, how soon, and how to keep the email and the ad from claiming the same order.

Welcome series: from paid click to subscriber

A signup form turns a one-time paid visit into a contact you can reach again without paying for another click. The welcome emails that follow decide whether the subscriber ever orders. Growing a list from paid traffic covers the signup offer, the first three emails and whether a signup should count as a conversion in Google Ads.

Post-purchase, replenishment and win-back: one timeline

After the first order, the messages come in sequence: thanks and delivery details, then an offer of a related product, a reminder to reorder consumables, and finally a win-back email. Post-purchase, replenishment and win-back emails shows how to place them on one timeline and when a customer counts as lost.

Back-in-stock and price-drop alerts

A shopper who reaches a sold-out bestseller has nothing to buy on that page. Offer to tell them when it is back, and you keep the contact. Back-in-stock and price-drop alerts explains which products deserve an alert and how to avoid teaching people to wait for discounts.

New arrivals: the campaign that shows your assortment is alive

A regular send can push a sale or show what is new. The second kind is how past buyers hear about products added since their last order. New arrivals and product launch emails covers how to give new products their first sales through email.

What do Gmail and Yahoo require before your first send?

Email deliverability is the share of your emails that reach the inbox instead of landing in spam or being rejected. Since February 2024, Gmail and Yahoo have had written requirements for anyone who sends email to their users. Gmail’s FAQ says that from November 2025 it is ramping up enforcement, including temporary and permanent rejections of messages that don’t comply.

Gmail counts you as a bulk sender once you send close to 5,000 messages or more to personal Gmail accounts within 24 hours. All messages from the same primary domain count together, subdomains included. One campaign to a large list can cross that line in a single day.

Your email tool handles most of the technical rows once you connect your domain. Check these yourself:

• Your email tool signs mail with your own domain. Gmail’s guidelines ask senders who use an email tool to verify that it authenticates their mail with SPF and DKIM.
• Only people who opted in get marketing emails. Gmail’s guidelines say not to buy address lists and to avoid signup boxes that are ticked by default.
• Receipts and promotions use different From addresses. Gmail gives the example of sales@ for receipts and deals@ for promotions.
• Volume grows gradually. If you send large volumes, Gmail advises starting low, with engaged recipients, and raising the volume slowly.

One-click unsubscribe applies to marketing and promotional messages. According to the Gmail FAQ, transactional messages such as password resets and reservation confirmations are exempt.

Why do your email tool, Google Ads and GA4 all claim the same order?

One question store owners bring to us is which number to trust. Google Ads shows one figure and the shop’s records show another. Email adds a third claimant. Each system counts the same order under its own rules and ignores the others.

Take one shopper. She clicks your Shopping ad, adds a product to the cart and leaves. Your abandoned cart email arrives, she opens it on her iPhone, and two days later she types your shop’s address and buys.

• Google Ads counts the order, because it came within the conversion window after her click. It doesn’t know the email exists.
• Klaviyo counts the same order, because she opened the email within 5 days. Its help page says that, by default, an automatic open by Apple Mail Privacy Protection also counts.
• GA4 ignores the direct visit. Under its paid and organic last click model, the credit goes to the last channel she clicked through, which was the ad.

If she had clicked the email instead, GA4’s paid and organic last click model would give 100% of the credit to Email. Its Google paid channels last click model would still give it to the last Google Ads click. Your shop still records one order.

So if you add email revenue to Google Ads conversion value, the sum is larger than what you sold. Attribution for online stores explains how each system splits credit and which number to use for which decision.

Performance Max adds to the overlap. According to Google Ads Help, it reaches all Google Ads inventory, including YouTube, Display, Search, Discover, Gmail and Maps, from one campaign. In our data, Performance Max runs in 141 of 146 stores and takes a median 95.7% of their ad budget (GetProfit data, June 2025 – June 2026). So for most stores, the ads that claim the same orders as their emails are Performance Max ads. Whether a separate remarketing campaign still pays on top of that is covered in remarketing for online stores.

Why can’t you trust the open rate any more?

Apple’s support page says Mail Privacy Protection prevents senders from seeing whether you opened their email. Klaviyo’s help page says that Mail Privacy Protection may record opens the subscriber did not make. It adds that, by default, such an automatic open can earn a conversion. So the open rate of Apple Mail users can be inflated, and an “open” can credit an order to an email nobody read.

Judge a flow by clicks and orders instead. Clicks are an action the recipient took. You can count orders in your shop.

How do you check that a flow adds orders?

The question is incrementality: how many orders would not have happened without the email. A holdout test answers it. Attribution reports can’t, because every model only splits credit for orders that already happened.

1. Pick one flow. Start with abandoned cart: it follows an ad click within hours, so it overlaps with your ads the most.
2. Hold out a random part of the audience. Send the flow to most people who enter it and nothing to a random 10–20%. If your email tool offers a random split inside a flow, use it. Otherwise, split by the last digit of the customer ID.
3. Fix the window before you start. For example, count orders placed within 7 days of entering the flow, in both groups.
4. Count orders in your shop, not in the email tool. Match orders to people by email address. The email tool has nothing to attribute in the holdout group, so only shop data treats both groups the same way.
5. Work out the difference. Extra orders = (order rate of the emailed group − order rate of the holdout group) × number of people emailed.
6. Compare with what the email tool reports. The gap between the two is the minimum number of orders the tool claims but the flow did not add.
7. Keep going until the holdout group has a few dozen orders. Until then, the result shows only the direction.

Example store, not client data.

In one month, 1,000 shoppers leave a cart in a tableware shop and can be emailed. The shop holds out 200 at random and emails the other 800. Within 7 days, 64 of the 800 order (8.0%), against 10 of the 200 (5.0%).

Extra orders: (8.0% − 5.0%) × 800 = 24. The email tool reports 52 orders for the flow, because that many buyers opened or clicked within its window. The flow added 24 orders, or 46% of what the tool claims. At least 28 of the orders it claims would have come anyway: through the ads, a search, or a typed address. At an average order value of 600, the flow added 14,400 in revenue, while the tool reports 31,200. Ten orders in the holdout group is too few for a precise number, so the shop keeps the test running.

Measuring email against Google Ads covers attribution windows, holdout tests for each flow and per-flow benchmarks.

A bestseller block goes stale in about three months

Most store emails carry a product block, such as “our bestsellers” or “you may also like”. If you filled that block once, when you built the template, it ages. In our study of 1.4 million products over 13 months, 64.7% of winners were one-offs: one conversion in one month, and then nothing. Of the bestsellers, 71% stayed in the top for no more than 3 of the 13 months, and a stable winner lasted a median 3 months.

A bestseller block made in spring can show last season’s products by summer. The study measured conversions from ads, not email clicks, so read it as a warning about any fixed product list. The fix is a routine: refresh the products in each block from current data, at least as often as the top changes.

The portal’s labels sort every product by how it behaves in ads, from Bestsellers to Dormant. The portal recomputes them with every data refresh, and you can export any group as a list. That gives you this month’s Bestsellers and Newcomers for an email’s product block. You load the list into your email tool, and the tool sends the emails. See how the portal labels your catalogue.

Stores that doubled got 47.3% of revenue from new products

Our analysis of 100 stores compared the first three months of June 2025 – June 2026 with the last three. In stores whose revenue doubled, 47.3% of revenue in the last three months came from products that were not there in the first three. In stores whose revenue declined, the share was 26.1%. Revenue here is what Google Ads recorded.

The link held whether stores cut, kept or raised their ad spend. It is an observation, not an experiment: assortment renewal goes together with growth, and our data doesn’t show which comes first.

For email, this means that if your shop keeps adding products, your past buyers learn about them only when you show them. A new-arrivals email is a direct way to give a new product its first sales from people who already know the shop.

Which email numbers are still worth watching?

Our own data has a clear limit: it comes from Google Ads accounts and holds no repeat purchases, customer lifetime value or email results. So every email figure in this guide comes from the source that published it, named next to the number.

A vendor report points the same way as this guide’s order of setup. Klaviyo’s 2026 benchmarks page says flows generate nearly 41% of email revenue from 5.3% of sends, with click rates of 5.58% against 1.69% for campaigns. The page doesn’t state its sample size. Klaviyo also counts that revenue with its own attribution, which can include orders your ads claim too. Treat it as the vendor’s view of flows against campaigns, not as a target for your store.

Where do SMS and messaging apps fit?

SMS and messaging apps are a separate channel, with their own consent rules and pricing. Choosing between SMS, Viber, WhatsApp and Telegram depends on what your shoppers in Ukraine, Czechia or Slovakia use.

The measurement rules stay the same. Tag links with utm_medium=sms, so GA4 files the visits under its SMS channel. Klaviyo uses the same 5-day default window for SMS as for email, so SMS needs a holdout test just as much.

Can your email list work inside Google Ads too?

Yes. According to Google Ads Help, Customer Match lets you use your online and offline data to reach and re-engage your customers. It works across Search, the Shopping tab, Gmail, YouTube and Display. You can upload your buyer list there. Customer Match for online stores covers list size, how often to refresh the list and how to upload it.

What to do this month

1. Check your sending domain. In your email tool, confirm that SPF, DKIM and DMARC pass for your domain and that marketing emails carry one-click unsubscribe. Add the domain to Gmail Postmaster Tools to see your spam complaint rate.
2. Tag every link. Use UTM parameters with utm_medium=email or utm_medium=sms and the flow name in utm_campaign. GA4 then puts the visits into its Email and SMS channels.
3. Launch the abandoned cart and browse flow first. Then the welcome series, then post-purchase emails. Keep promotions out of receipts.
4. Add a random holdout group to each flow from the first day. It costs a few orders now and gives you the only number that shows whether the flow adds orders.
5. Refresh product blocks monthly. Fill “bestsellers” and “new in” from current lists instead of the products you picked when you built the template.
6. Report orders from your shop. Keep email revenue and Google Ads conversion value apart, because both count the same orders.
7. Review each flow once its holdout group has a few dozen orders. Keep flows that add orders. Change or stop the rest.

Which products bring money in and which spend it. Every product gets its own label based on how it behaves in ads — from bestsellers to dormant ones that spend budget without a single sale. The portal changes nothing without your consent.

Label your catalogue →

Sources

• Email sender guidelines — requirements for all senders and for senders of more than 5,000 messages a day to Gmail since February 2024: SPF or DKIM, SPF and DKIM plus DMARC with a “none” policy, From alignment, spam rate below 0.3% in Postmaster Tools, one-click unsubscribe and a visible link for marketing messages, DNS and TLS; advice on opt-in, purchased lists, pre-ticked boxes, separate From addresses, no promotions in receipts, gradual volume growth, provider authentication. Checked 2 October 2026.
• Email sender guidelines FAQ — enforcement ramping up from November 2025 with temporary and permanent rejections; the definition of a bulk sender (close to 5,000 messages in 24 hours, counted by primary domain); spam rate below 0.1% recommended; transactional messages excluded from one-click unsubscribe; unsubscribes within 48 hours recommended. Checked 2 October 2026.
• New Gmail protections for a safer, less spammy inbox — Google’s announcement of the bulk sender requirements, starting February 2024. Checked 2 October 2026.
• Sender Best Practices — Yahoo’s requirements: SPF or DKIM and spam rate below 0.3% for all senders; SPF, DKIM, DMARC, one-click unsubscribe and honouring unsubscribes within 2 days for bulk senders. Checked 2 October 2026.
• About conversion windows — the default click-through conversion window of 30 days for a new conversion action and how to change it. Checked 2 October 2026.
• Create conversions from Google Analytics events in Google Ads — Google Ads measures conversions only from Google Ads sources, Analytics can include other sources; differences between the two are common even with a correct setup. Checked 2 October 2026.
• Get started with attribution — GA4 models exclude direct visits from credit; path examples for paid and organic last click (100% to Email) and Google paid channels last click. Checked 2 October 2026.
• Default channel group — the GA4 Email channel (source or medium “email”) and SMS channel (source or medium “sms”). Checked 2 October 2026.
• URL builders: Collect campaign data with custom URLs — the utm_source, utm_medium and utm_campaign parameters, with email examples. Checked 2 October 2026.
• About Performance Max campaigns — Performance Max reaches all Google Ads inventory, including YouTube, Display, Search, Discover, Gmail and Maps, from one campaign. Checked 2 October 2026.
• About Customer Match — Customer Match uses your online and offline data to reach and re-engage customers across Search, the Shopping tab, Gmail, YouTube and Display. Checked 2 October 2026.
• Understanding message conversion tracking — Klaviyo’s last-touch attribution, the default 5-day window for email and SMS in newer accounts, and conversions counted after opens, clicks or, by default, automatic Apple Mail Privacy Protection opens. Checked 2 October 2026.
• Email marketing benchmarks by industry — Klaviyo’s figures for flows against campaigns: share of email revenue, share of sends, click rates; the page does not state its sample size. Checked 2 October 2026.
• Use Mail Privacy Protection on iPhone — Mail Privacy Protection prevents senders from seeing whether you opened their email. Checked 2 October 2026.
• GetProfit study of 1.4 million products, 130+ stores, 13 months — share of one-off winners, how long bestsellers stay in the top.
• GetProfit data: 100 online stores, June 2025 – June 2026 — share of revenue from new products in stores that doubled and in stores that declined.
• GetProfit data: 146 online stores, June 2025 – June 2026 — Performance Max in 141 stores and its median share of ad budget.
• GetProfit portal — product labels, recomputed with every data refresh, and export of any group as a list.