About this time of the year I get many emails about polishing silver. I always ask if the silver is plated or if it is sterling, because it does make a difference. Polishing silver actually removes a small amount of the silver to reveal clean metal underneath.
Plated silver is not all created equal. Some décor pieces are lightly plated, and if you use polish too much, you will remove the silver plating. So always know what you are working with.