The verdict in three sentences
An automated post-purchase sequence — thank-you, review request, replenish reminder, winback — generates repeat revenue for pennies per message. In Johannesburg in 2026, this flow adds 15% repeat revenue, of which 8% comes from the replenish reminder alone. It is the highest-yield automation: once configured, it runs by itself and works on every customer at no marginal cost.
The sequence that works by itself
Every message has a role and a precise moment. The channel is chosen by cost and urgency: SMS for short transactional, email for content, WhatsApp for high-open-rate engagement.
| Step | Timing after purchase | Channel | Goal | Revenue uplift |
|---|---|---|---|---|
| Thank-you + order tracking | Immediate | SMS + email | Reassure, reduce disputes | — |
| Review request | Day +4 | Social proof | Indirect | |
| Usage tips | Day +10 | Satisfaction, fewer returns | +2% | |
| Replenish reminder | Product-dependent | SMS + WhatsApp | Rebuy the consumable | +8% |
| Product recommendation | Day +30 | Cross-sell | +3% | |
| Winback | Day +60 no purchase | WhatsApp + discount | Recover dormant | +11% |
In Johannesburg, a winback at 60 days of inactivity recovers 11% of dormant customers — the most profitable message in the whole sequence, because it revives revenue already lost.
The replenish window drives all the yield
The replenish reminder only works if it lands just before the customer runs out. This window depends on the product: too early, they ignore it; too late, they've rebought elsewhere.
| Product type | Replenish window | Message cost | Repeat uplift |
|---|---|---|---|
| Cosmetics / skincare | 30 to 45 days | 15 FCFA (SMS) | +9% |
| Supplements / vitamins | 25 to 30 days | 15 FCFA (SMS) | +12% |
| Groceries / consumables | 14 to 21 days | 0 FCFA (WhatsApp) | +14% |
| Cleaning products | 40 to 60 days | 15 FCFA (SMS) | +7% |
| Fashion / accessories | No replenish (recommendation) | — | +3% |
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The cost is trivial: a 15 FCFA SMS or a free WhatsApp message against a recovered basket of several thousand francs. The return on a well-tuned replenish reminder often exceeds 50 to 1.
Mini case study
Thandiwe sells cosmetics and supplements online in Johannesburg: 1,000 orders a month, 19,000 FCFA average basket. She sets up the full post-purchase sequence. The Day +30 replenish reminder (+8% revenue) plus the Day +60 winback (+11% of dormant) add, with the other steps, about 15% repeat revenue. On 19 million FCFA of monthly revenue, that is 2.85 million FCFA extra. Message cost: about 25,000 FCFA of SMS per month, WhatsApp free. The setup, a one-off around 450,000 FCFA, pays back in under a week.
FAQ
SMS or WhatsApp for post-purchase? Both, depending on the step: SMS for short transactional (15 FCFA, arrives everywhere even without data), WhatsApp for engagement (free, +80% open) such as review requests and winback.
When should I send the replenish reminder? Just before the estimated run-out: 25-30 days for supplements, 14-21 days for groceries. Well tuned, this window adds 8 to 14% repeat for a 15 FCFA message.
Is the 60-day winback worth a discount? Yes: in Johannesburg it recovers 11% of dormant customers, revenue already treated as lost. A 10% discount on this segment stays highly profitable.
What does a post-purchase sequence really cost? Setup is once; then the monthly cost is limited to SMS (about 15 FCFA each) and WhatsApp (free). The return often exceeds 50 to 1 on replenishment.
Let's talk about your project. We configure your post-purchase SMS + WhatsApp sequence and your replenish windows. WhatsApp +221 77 596 93 33.
Mohamed Bah
Fondateur, Kolonell
Passionate about digital and entrepreneurship in Africa, Mohamed has been helping Sénégalese businesses with their digital transformation since 2020. Founder of Kolonell, he believes every SME deserves a professional and accessible online présence.
