One other rthing to consider... Small hotels, whether family-run or corporate, have less margin for error. Even if they don't overbook, prior guests may overstay, or rooms may become unrentable due to burst pipes, broken A/C's, etc. If a big hotel loses 1 room of 1000, it will likely be able to absorb the loss and find a room for the guest a lot easier than a small hotel or B&B losing 1 room out of 10.