Product review (5 stars): Surprisingly effective!
My new fridge was driving me crazy with these deep, low frequency vibrations that permeated the entire house.  It wasn't obvious that the sound was traveling through the feet of the refrigerator, so I was doubtful that these anti-vibration pads would help much.  However, it ended up working beautifully.  I still have a loud fridge, but the sound no longer travels to other rooms in the house.