I like the look of this poster. It’s a pretty straightforward interpretation of the title, but it looks good and is scary enough. I think the whole beaten up motel look has become tightly associated in our brains with “bad things” due to countless horror movies, and that help the poster be more effective in creeping us out.
But, the poster tells us very little about the movie, and why we would want to see it. That is a real problem. Perhaps a smart tagline could have made things better. Perhaps not. But as it stands I think this is a nice poster which just might be doing a bad job of selling the movie.