Email marketing is the practice of using an owned list of subscribers and customers to drive revenue through campaigns and automated flows. Campaigns are one-off sends — a launch, a sale, a newsletter. Flows are triggered sequences that run automatically based on behaviour, such as welcome series, abandoned cart, browse abandonment, post-purchase, and winback.
The defining characteristic is ownership. Unlike paid channels, an email list is an asset you control: no algorithm decides how much of it you reach, and no auction sets the price.
Why Email Marketing Matters for Ecommerce
D2C economics generally do not work on first orders. Between acquisition cost, packaging, shipping, payment fees, and returns, the first purchase often contributes little or nothing. Profit arrives with the second and third orders, and email is the cheapest reliable way to produce them.
The concentration of value in flows rather than campaigns surprises most teams. Automated sequences typically generate the majority of email revenue while representing a small fraction of the sends, because they reach people at moments of genuine intent — the shopper who just abandoned a cart, the customer approaching the end of a bottle. Campaigns reach everyone regardless of readiness.
In the Indian market, email sits alongside WhatsApp rather than replacing it. Open rates for WhatsApp are dramatically higher, but the channel is easier to over-use and carries more risk of irritating customers. Most well-run D2C programmes now use both: WhatsApp for time-sensitive and transactional messages, email for longer content, product education, and anything the customer might want to refer back to.
Deliverability is the constraint nobody thinks about until it breaks. Sending to unengaged addresses month after month degrades sender reputation until even engaged customers stop seeing messages.
Real-World Example
A tea brand sent one weekly newsletter to their entire list and had no automated flows at all. Email produced about 6% of revenue.
They built four flows: a welcome series explaining sourcing and brewing, an abandoned cart sequence, a post-purchase sequence with brewing guidance timed to arrival, and a replenishment reminder calculated from pack size and typical consumption — around day 24 for a 250g pack.
Email revenue reached 23% of total within four months. The replenishment flow alone outperformed every campaign they had ever sent, because it arrived at the moment the customer was actually running out. They also cut the newsletter from weekly to fortnightly and saw open rates rise, having been sending more often than they had things worth saying.
How to Improve / Optimize Email Marketing
- Build flows before campaigns. Welcome, abandoned cart, post-purchase, and replenishment cover most of the available value and run without ongoing effort.
- Time replenishment to actual usage. Calculate from pack size and consumption rate rather than sending a generic monthly reminder.
- Segment by behaviour. Recent buyers, lapsed customers, and never-purchased subscribers need different messages. One send to everyone underperforms all three.
- Protect deliverability. Suppress addresses that have not engaged in six months. A smaller engaged list outperforms a large stale one.
- Coordinate with WhatsApp. Decide which channel owns which message rather than sending both and irritating people twice.
- Measure revenue per recipient. Open and click rates are diagnostic; revenue per recipient is the number that compares a campaign to a flow honestly.
Email Marketing in A/B Testing
Email is a natural testing environment: sends are discrete, audiences are randomisable, and results arrive quickly. Subject lines, send times, offer framing, and flow timing are all worth testing, with revenue per recipient as the primary metric rather than open rate.
The connection to on-site testing is worth making deliberately. Email traffic arrives with known context — you know who they are, what they bought, and which message brought them — which makes it one of the best-qualified audiences for personalization. Sending a replenishment email that lands on a generic homepage wastes most of what the email established. CustomFit.ai supports targeting by campaign parameters, so email visitors can be shown a landing experience matching the message that brought them and measured separately.
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