Either half-pages or full-pages. With hotel guests paying more attention and listening to in-room advertising than any other ad medium, give yourself enough space to convey your message. Got a menu you want to highlight? A map for how to walk to your location? A really cool pic and message? This is the perfect place to show them.
"They'll just go to Google or Yelp to find a place" has never been more wrong. According to Gallup, a whopping 78% of hotel guests still use in-room directories when looking for suggestions of nearby businesses, DESPITE having internet connections. Hotel guests don't want commercial, they want local.
Hotels receive tens or hundreds of THOUSANDS of guests every year. What would you say to them if you had the chance to get in front of each and every single one?