A replenishment email reminds a customer to re-order a consumable product around the time they are likely to run out. It is one of the highest-return retention flows in ecommerce because it reaches a known customer with a relevant product at a moment of genuine need. The timing that works comes from the individual customer’s purchase behaviour and the product’s consumption cycle, estimated per customer, rather than a single calendar interval sent to everyone.
Why fixed-interval reminders underperform
The simplest replenishment flow sends every buyer of a product a reminder a set number of days after purchase. It captures some demand, but it misses on both sides. Heavy users have already run out and re-ordered elsewhere by the time the reminder lands. Light users receive a prompt while they still have plenty, which reads as noise and trains them to ignore the sender. A single interval cannot fit a population with different consumption rates.
Timing from behaviour
A better estimate comes from the customer’s own signals. Hello Retail Triggered Emails sends behaviour-driven emails from data captured on the storefront, so the prompt can be tied to purchase history rather than a flat schedule. Hello Retail Product Agents identify the next logical step in each customer journey, including a replenishment, at the relevant moment, which moves the reminder from a fixed date toward the point the customer is actually likely to re-order.
Beyond the refill: the next best action
Replenishment is one move in a wider retention motion. Hello Retail Product Agents are an agentic retention product positioned around maximising revenue from existing customers, and the next best step is not always a refill. It may be an accessory that pairs with the original purchase, a price-drop prompt on a product the customer already buys, or a relevant alternative. Hello Retail Product Recommendations rank these options per shopper using behavioural signals, so the follow-up matches the individual rather than a category default.
A setup checklist
To move from fixed-interval to behaviour-timed replenishment:
- Identify repeat-purchase products: consumables with a recognisable re-order cycle.
- Estimate per-customer timing: base the send window on the customer’s purchase history, not one global interval.
- Personalise the contents: rank the featured products per shopper rather than showing one list.
- Plan the next best action: sequence accessory, price-drop, and alternative prompts for customers who are not due a refill.
- Measure re-order rate: track conversions from the flow rather than opens, so the timing can be tuned.