Your website says nine units. Your stockroom has six. The other three sold at the register sometime in the last hour and until your online listing catches up, whoever orders them next is buying inventory that doesn’t exist. That mismatch is where almost all overselling actually comes from. Not bad luck. A sync problem. This guide covers why it keeps happening even at stores that call themselves “integrated,” what a real-time sync setup actually needs to do differently, and a five-minute test you can run today to find out if you’re currently exposed. 📋 In This Guide What “real-time” actually means