Customers keep asking us why we do not manage inventory.
The short answer: Quantities are transactional. Prices are not.
(Don’t worry, this is the last technical term for today.)
Clear separation of responsibilities
ERP = single source of truth for quantities ✅
- aggregates sales across all marketplaces (Amazon, eBay, …)
- maintains a central available stock level
- distributes inventory deterministically to marketplaces
- prevents overselling through synchronous stock reduction
- …
RePricer = decides prices only
- calculates and writes prices only
- reads inventory at most read-only
- never writes quantities 🚫
That is exactly why a RePricer should not manage or write quantities.
Why “a RePricer that manages quantities” is dangerous
Example 1 – Even a “current” Amazon report is just a snapshot
- Amazon inventory = 10
- RePricer loads the inventory report (snapshot at T₀)
- Between T₀ and processing, a sale happens → inventory drops to 0
- The report still shows 10 (snapshot)
- RePricer incorrectly treats the report as “truth”
- RePricer writes 10 back to Amazon → inventory is artificially increased → overselling becomes possible
Example 2 – Multichannel interference
- Total inventory = 10
- Sale on eBay → ERP reduces inventory to 9
- ERP sends 9 to Amazon
- RePricer still knows 10 (outdated DB state)
- RePricer sends 10 to Amazon → Amazon inventory jumps back up → inventory is effectively increased
Example 3 – Feed race condition
- RePricer sends a feed with inventory = 10
- Shortly after, ERP sends inventory = 0
- Amazon processes the ERP feed first
- Later, the repricer feed is processed → old inventory wins
Conclusion
When a repricer writes quantities, it almost always produces inconsistencies and overselling in practice.
Prices → RePricer 💶
Quantities → ERP / WMS 📦