Reseller crosslisting apps fail to auto delist sold items across Poshmark Mercari eBay causing double sales

Resellers who list the same one of a kind inventory across Poshmark, Mercari, eBay and Depop rely on crosslisting apps to auto delist an item everywhere once it sells on one platform. The auto delist breaks constantly. Items sell, do not get pulled from the other marketplaces, then sell again, forcing the reseller to cancel orders, eat penalties and apologize to buyers. Sellers also report the apps losing marketplace connections and needing re auth multiple times a month, and entire platforms (Mercari, Facebook) being down for months. The crosslisting space has incumbents (Vendoo 2594 App Store ratings, OneShop 465 ratings) but the core reliability promise keeps failing, which is the real gap.