The verdict in three sentences
The ROI of a vertical app is calculated before the purchase, not after: just compare the annual gain (time saved, errors avoided, extra revenue) to the annual cost (amortized development + maintenance). The formula is simple: ROI = (annual gain - annual cost) / annual cost. Practical decision rule: a project is solid if its ROI exceeds 100 % over 18 months, meaning it repays more than its cost and starts generating net profit.
The three sources of gain to quantify
A credible ROI adds up concrete gains, not vague promises. Three items are enough to build the estimate.
| Source of gain | How to quantify it | 2026 example |
|---|---|---|
| Time saved | Hours/week x hourly cost x 52 | 10 h x 3 000 FCFA x 52 = 1 560 000 FCFA/year |
| Errors avoided | Count x unit cost of an error | 4/month x 15 000 FCFA x 12 = 720 000 FCFA/year |
| Extra revenue | Reminders, fewer no-shows, sales | 10 % more recurring revenue |
Time savings are the easiest to measure and often the largest: 10 hours a week valued at 3 000 FCFA/h already represent about 1 500 000 FCFA per year.
Compare total cost to benefit
Cost is not just the purchase price. You must spread development over its useful life and add maintenance.
| Cost item | Order of magnitude FCFA | Basis |
|---|---|---|
| App development | 800 000 - 5 000 000 | Amortized over 3 years |
| Annual maintenance | 480 000 - 1 800 000 | 40 000 - 150 000/month |
| Team training | 100 000 - 400 000 | One-off |
| Total annual cost | 700 000 - 3 400 000 | Dev/3 + maintenance |
Against that, if the annual gain clearly exceeds this annual cost, ROI is positive. A project at 2 000 000 FCFA of development (i.e. 667 000 FCFA/year amortized) plus 600 000 FCFA of maintenance costs 1 267 000 FCFA/year; against 1 560 000 FCFA of gain, the annual ROI is about 23 %, and far higher from the second year.
Mini case study
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Aminata is unsure about buying an app at 2 400 000 FCFA for her firm. She estimates 8 hours saved per week valued at 3 500 FCFA/h, or 1 456 000 FCFA/year, plus 500 000 FCFA/year in avoided billing errors: 1 956 000 FCFA of annual gain. Her annual cost is 800 000 FCFA (dev amortized over 3 years) plus 600 000 FCFA of maintenance, i.e. 1 400 000 FCFA. ROI is (1 956 000 - 1 400 000) / 1 400 000 = about 40 % in the first year, and climbs above 140 % once development is fully amortized. The decision is clear: she buys.
FAQ
Over how many years should development be amortized?
Three years is a prudent basis for a vertical app. If the tool stays relevant longer, the real ROI beats the initial estimate, since only maintenance cost remains.
How do I quantify extra revenue without overstating it?
Stay conservative: base it on a cautious percentage (for example 10 % of reminders converted) rather than the best-case scenario. A credible ROI survives a pessimistic assumption.
What ROI threshold justifies the purchase?
A common rule targets ROI above 100 % over 18 months, meaning a project that repays more than its cost and starts generating net profit within that window.
What if I cannot estimate my time savings?
Time a typical week: note the repetitive tasks (billing, follow-ups, double entry) the app would remove. This concrete measurement replaces guesswork and makes the calculation reliable.
Let's talk about your project. We will quantify the ROI of your future vertical app together, using your own figures. 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.
