My wife and I showed up at the Colonial Acres Resort in West Yarmouth for our stay, which had been confirmed through Expedia days before (including a confirmation message from the hotel itself), only to be told by the front desk staff that there was no room available for us and that they could not honor our reservation, due to over-booking. We had to book another hotel at the last minute (it was around 6 PM), ended up paying a much higher rate than our original booking, and had to cut our vacation short by a day to conserve money.
Expedia, to its credit, compensated us for our trouble. Expedia also told us that we were not the only ones whose confirmed reservation this hotel had refused to honor recently. I'd say at a minimum this hotel is disorganized and incompetent, and it's possible that they are deliberately engaging in shady over-booking practices. I strongly recommend avoiding this place until they get their act together!