You'd certainly be inviting a criminal trespass issue. Hotels are there to run their business, not provide a captive audience for your advertising. The hotel could also potentially sue you in civil court, asking for damages in that their staff would have the additional burden of cleaning up flyers placed in empty rooms, plus loss of reputation for the hotel (start counting that in the tens of thousands of dollars) as being one where ads are slipped under doors. I know that in various counties in Florida hotels have requested, and police have obliged, in bringing charges for criminal mischief in one county, and for vandalism in another. How probable that might be in the county in your scenario, only the local PD can answer. Nevada and Florida both have huge tourism business that is highly competitive, and anything that makes an establishment look bad isn't going to go by quietly. Bottom line is that yes, if you're on hotel property conducting business (like passing out flyers) without permission of the property owner, you can face both civil and criminal issues. Bottom line: get permission, or get lost.