The coolest thing about Floor Graphics is that you have almost unlimited advertising space and very little competition. A lot of convention centers will allow you to put floor graphics in the aisles to drive traffic towards your booth, but not many people actually do. If you use the removable adhesive type, the floor can't be carpeted, so call the venue first and make sure that it's ok.
Another cool thing about the adhesive floor graphics, is that they can be die-cut into any shape. Think of the potential with this; arrows pointing towards your booth, or footprints leading the way. You could print in four color process on the graphics and showcase your product as people walk by. Imagine printing something that looks like a dollar bill on your graphic. Talk about getting attention, you will have people literally stopping and bending over to try and grab it. Yalk about having a potential consumer's complete attention!
A different type of 'floor graphics' that I love, that not many people think about, is the customized carpet. As a frequenter of conventions and trade shows as an attendee, walking on concrete for 8 hours can be hard on the feet, back, and knees. Having a nice, plushy carpet in your booth will encourage people to come back just so they can have a sigh of relief as thepressure is relieved on their feet. (Plus, you get to stand on comfy, plushy carpet for 8 hours too).
Check out our very self-explanatory (But effective) floor graphic: