This is my first time purchasing an ear warmer, and I was skeptical about its ability to both keep my ears warm and stay on.  After having used this product several times, I am pleasantly surprised.  Its stretch design across the back is not awkward and keeps the ear covers in place well.  I don't know that it would stand up to any kind of exertion, but for a man doing yard work, walking to the bus, and similar tasks, it works great.  The ear covers are warm enough and thick enough to block the wind and provide some insulation, but not so thick as to be unwieldy and block all sound.  Overall, I am quite pleased with this product.

EDIT (3/8/14): After having worn these for a year I have chosen to drop two stars from my original review.  While I do still use them, I have found that they tend to slide up, down, or back on the ears.  Any time I wear a hat with them, or put on a coat with any kind of collar, they get pushed off the ears pretty easily.  For walking to and from the bus or car these are still just fine, but if I am doing anything involving more movement (moving snow, going for a hike, etc) they just aren't worth wearing.