smallcompany - 4:36 am on Feb 12, 2010 (gmt 0)
Few things that Google may use in that case:
Is there a geo related keyword in your query?
IP address. I have no idea if it's possible that your hotel may have US related IP.
Personalized search. Are you logged into your Google account? Google thinks you're crazy about your ads. ;)
Couple of resources: