we wrote in out std brochure that there are tons of hotels in pv, but this is where we're staying, and should you choose to stay elsewhere, there's a fee. everyone wound up staying w/ us, but 1 or 2 not, we would have paid. if there were more, we would not have.
have you told your guests that you'd pay? if not, make it clear that you won't, and maybe they'll be more likely to choose your hotel!