Sellermania is a French SaaS platform for marketplace management. It gives professional sellers and refurbishers a single interface to publish product feeds, synchronize stock in real time, centralize orders, and reprice automatically across all their marketplaces and CMS. Sellermania is the only marketplace feed manager that keeps a live copy of your inventory. Stock updates reach all your channels in under 5 minutes, compared to 2 to 4 hours with competing solutions. No overselling. No lost orders. WeReprice, Sellermania's native dynamic repricing engine, adjusts prices in real time across 70+ marketplaces without relying on a third-party tool. Competitive strategies, Buy Box targeting, and margin protection, all built in. For refurbishers, Sellermania handles grade management, per-marketplace listing rules, and Amazon Renewed or Back Market compliance without manual workarounds. Trusted by 30 of the top 100 Amazon sellers. 20 years of marketplace expertise. 100M+ products managed daily. 300M€ in refurbished sales processed annually.