We've had a suggestion box for quite some time at my library. All suggestions are seen by our library director. Then, I respond to any suggestions where the person has included contact information. However, most people don't include contact information, and those suggestions just go in a file in my office.
I'm not sure I'd feel particularly inclined to submit a suggestion if I had no idea who even looked at it.
So I decided a display was in order. We have an "art wall" (I use quotes because it's probably never been used as an art wall and is in the most inconvenient location imaginable) near the suggestion box, which the other librarians suggested as a location for this display. On the wall, I taped a number of questions along with our responses with plenty of room for expansion. Someone also left the comment "More cowbell" not too long ago, and we all agreed that should be included. The response is simply a picture of Will Ferrell and the cowbell, with text below reading "We agree!" Humor is always good. :)
I also made the suggestion box slightly more noticeable with an additional sign that says "How Are We Doing?"
Here's hoping we get some response!