Promotional prices are the number-one conversion lever in e-commerce. They are also the number-one trap: regulator compliance, forgotten end dates, desynced feeds. Here is how to execute them cleanly, without piling up tools.
The 3 promotional price mechanics
Percentage discount
Flat value discount
Target price displayed
The legal frame: Omnibus directive + 2015 French decree
Since May 2022, any promotional reduction must display the lowest price actually applied over the 30 days before the promo as the reference. No more MSRP, no more "normally 89 EUR" when you never sold at 89 EUR.
The 4 steps of a compliant promo
- Identify the reference price — 30-day low. Shopify keeps 90 days of history, Seegea 365 with full diff.
- Compute the promo price — respecting your minimum margin policy.
- Fill strikethrough + promo price + end date — Shopify via compare_at_price, PrestaShop via specific price.
- Refresh outbound feeds — Google Shopping, Meta, marketplaces. Without refresh, ads desync and can get suspended.
Seegea syncs everything in one click
The 3 costly mistakes
1. Non-compliant reference price
Crossing out the MSRP when it was never your actual price: deceptive commercial practice, up to 300,000 EUR fine. Seegea alerts if compare_at_price exceeds the 30-day low.
2. Forgotten end date
A promo that runs 3 weeks instead of 10 days because no one thought to stop it. On 2,000 products, that's thousands of euros of silent margin loss. Seegea schedules the auto revert to full price.
3. Feed desync
Site shows 49 EUR, Google Shopping 69 EUR. Result: Merchant Center suspensions, wasted ad spend. Seegea triggers the refresh immediately.
Comparison: tools to run a promo on 1,000 SKUs
| Task | Native backoffice | Seegea |
|---|---|---|
| Apply —20% on 1,000 SKUs | 3 to 5 hours | 30 seconds |
| Schedule promo end | Paid third-party app | Native + auto rollback |
| Omnibus non-compliance alert | No | Yes |
| Google Shopping feed refresh | Manual | Auto on every push |
| Rollback if mistake | Listing by listing | Ctrl+Z on full bulk |
| History of past promos | 90 days | 365 days |
Run promos without the stress
30-min Google Meet · we prep a real promo on your catalog
Case study: weekend flash sale on 800 SKUs
Steps executed on a Seegea customer in March 2026:
- Thursday 5pm: export of 30-day low (one click), CFO validation of the list.
- Friday 7am: apply —25% on 800 filtered SKUs (45 seconds).
- Friday 7:02am: automatic Google Shopping feed refresh.
- Sunday 11:59pm: scheduled auto end, revert to full price.
- Monday 8am: history review, result export.
Total marketing team effort: 15 spread-out minutes. Previously via native backoffice: 2 person-days, with 3 compliance mistakes caught after the fact.
Promotional pricing and official sales periods
During sales periods (twice a year in France, set by prefecture), selling below cost is allowed. The reference price still remains the price applied over the 30 days before the sales period. Successive markdowns are allowed, but each new markdown must display the initial reference price.
Conclusion
A promotional price: 5 legal rules and 500 operational variables. Seegea handles the 500 variables so you can focus on the 5 rules. Created in France between Annecy and Chantilly, built by and for e-commerce operators who wanted to stop stressing at every promo.