The chair mat I bought is not nearly as durable as I would have thought. My chair is making indents in the material very easily and quickly. I hope it lasts as long as the last one I had (about 10 years).
This is the second chair mat I've bought from Staples at this price point for use on medium-depth household carpet. The previous mat lasted just three years before cracking badly enough to be unusable. This mat is clearer and looks thinner but after several it seems to be holding up better. My rolling chair hasn't worn any grooves into it. I wish it were a heavier more durable plastic but am hopeful that it will last longer. Note to other buyers: if you buy this mat rolled up let it warm and soften for about a day before trying to unroll it. Once you get it unrolled with the smooth side upward let it relax for another day. It will flatten fully but it takes a little patience.
This mat is too "light weight" for my purpose sitting on a fairly plush carpet. It is smooth on both sides so slides around and bunches up where I anchored it under the leg of my desk. My mistake.