The verdict in three sentences
An 11-store optician chain around Amsterdam already owns its most valuable asset: 26,000 active customers whose glasses come up for renewal roughly every 2 years. A custom app layer connected to the existing point-of-sale system turns that base into booked eye tests, targeted reminders and insurance quotes followed through to a sale, with a realistic target of 15% more sales. Kolonell prices this kind of project at 2,500,000 to 15,000,000+ FCFA (EUR 3,810 to 22,870+) depending on complexity, with anything else set in the quote.
Why the point-of-sale system is not enough
Optical retail software handles sales, stock, prescriptions and lab orders well. It is weak on three things that drive a chain's revenue. First, reminders at the right time: Dutch basic health insurance does not cover adult glasses, so customers rely on supplementary insurance, which typically reimburses EUR 100 to 250 every 2 or 3 years, and a reminder just as that budget renews converts well. Second, online booking for in-store eye tests by optometrists, which customers now expect in the evening and at weekends. Third, quote follow-up: a quote for progressive lenses that nobody chases ends up at a competitor.
The goal is not to replace the point-of-sale system but to build an app on top that reads its data through an API or export and runs customer relations for all 11 stores.
| Need | Optical POS software | SaaS booking tool (2026 order of magnitude) | Kolonell custom layer |
|---|---|---|---|
| Sales, stock, lab orders | Yes | No | Stays in the POS |
| Online eye test booking | Rarely | Yes, EUR 30 to 80 a month per store | Yes, calendar per optometrist and store |
| 2-year renewal reminder | Manual list export | No | Automatic, SMS and email |
| Quote follow-up | Basic status | No | Reminders at day 3 and day 10, per-store dashboard |
| Consolidated view of 11 stores | Depends on vendor | Partial | Yes, by store, staff member and campaign |
| Cost | Existing licence | EUR 4,000 to 10,500 a year for 11 stores | 2,500,000 to 15,000,000+ FCFA (EUR 3,810 to 22,870+), rest in the quote |
The features that pay
The first source of value is the renewal reminder. On a 2-year cycle, about 13,000 customers come due each year. The app segments them (progressive lenses, children, contact lenses), picks the channel and offers an eye test slot in their usual store. The second is the quote follow-up: each quote is dated, chased at day 3 and day 10, and the owner sees conversion by store. The third is the online calendar, which fills quiet Tuesday mornings instead of overloading Saturdays.
Prescriptions and eye measurements are health data, a special category under Article 9 of the GDPR, supervised in the Netherlands by the Autoriteit Persoonsgegevens. If the app stores them, you need a data protection impact assessment, encryption, role-based access and EU hosting. A lighter option is to store only the renewal date and leave prescriptions in the POS.
| Lever | 2026 assumption | Estimated annual effect |
|---|---|---|
| Customers due for renewal | 13,000 a year | Campaign base |
| Spontaneous return rate | 45% | 5,850 visits |
| Return rate with reminders | 53% | 6,890 visits, 1,040 more |
| Visit to sale conversion | 60% | 624 extra sales |
| Average basket, frame and lenses | EUR 350 | EUR 218,400 revenue |
| Quotes recovered by follow-up | 5% of 4,000 quotes | 200 sales, EUR 70,000 |
| SMS cost | EUR 0.07 per SMS, 30,000 sends | EUR 2,100 |
Timeline and watch points
Allow 3 to 4 months for a first release with booking, reminders and quote tracking, then a second release for a customer mobile app or loyalty scheme. The decisive technical point is access to POS data: official API, read access to the database or a daily export. It drives cost and should be confirmed with the vendor at scoping.
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Daan, owner of the 11 stores, turns over about EUR 7,150,000 a year, EUR 650,000 per store. Renewal reminders bring EUR 218,400 and recovered quotes EUR 70,000, a total of EUR 288,400, about 4% growth: the app does not deliver the full 15% on its own, it provides the measurable base. At a 60% gross margin, additional margin reaches EUR 173,040. Against a medium-complexity build at the top of the range, EUR 10,670, Standard maintenance of EUR 1,368 a year and EUR 2,100 of SMS, the project pays for itself in under one month of additional margin.
FAQ
Do we need to change our POS software?
No, the app connects to the existing system. The only condition is data access, by API or daily export, which most vendors can provide within 2 to 4 weeks.
How do we avoid spamming customers?
Frequency is capped, for example 2 messages per renewal and 4 a year at most. SMS consent is collected in store and unsubscribing takes one click.
Is health data a blocker?
No, but it requires a DPIA, encryption and EU hosting if prescriptions are stored. Keeping only the renewal date cuts the regulatory scope significantly.
Does each store keep its own calendar?
Yes, each store and optometrist has a calendar with 20 to 30-minute eye test slots. Head office sees utilisation for all 11 stores on one screen.
How soon do results show?
The first campaigns start when the first release goes live, after 3 to 4 months. Bookings from reminders are measurable within the first 4 weeks.
Let's scope your project. We define with you the stores, the data available in your POS and the priority campaigns for a first release delivered in 3 to 4 months. Detailed quote within 48 h. 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.
