Elevated food dishes are said to help prevent bloat because when the dog bends over to eat or drink if the dish is on the ground, it causes them to "gulp" their food, thus taking in and swallowing more air. They're also good to use for older dogs that have arthritis or other back/neck/joint problems because it's less stress on the joints and/or other infected areas.

We have one and Molly uses it from time to time. Both of my girls seem to prefer "regular" food dishes, though.