Double bookings from a sync that quietly drops
A guest books your Saturday on VRBO. The signal to your channel manager either never fires or fires 6 hours late. Meanwhile, another guest books the same Saturday on Airbnb. Now you're cancelling one of them, eating the Airbnb penalty, and watching your search ranking drop. Every channel manager will eventually have a sync hiccup. What matters is whether someone is watching for it. Operators who don't have a daily sync-check are leaking 1–2 double bookings a quarter.