Although I haven't released a book yet, I might try to release in a hotel soon. I think leaving it in the lounge area of a hotel might be a good idea. If there ae chairs next to the concierge's desk, you can leave it there: someone who is bored in the line to speak with the concierge is likely to pick it up. Another good thing about releasing in hotels is that your books will probably travel very far, since people might take the book back to their hometown.
I hope this helps! :)
I would always ask the hotel staff if this is okay first. The same with cafes and the like. I have never had a no yet, but it could happen. Also it's good if the staff know what the book is about, or they might throw it out.