I have a 1/4" pile carpet and the casters from my desk chair sink into the mat and make it difficult to move the chair. That is precisely what I was trying to avoid by buying the mat!
You get what you pay for. Though my carpet is very thin the mate gets indentations from the chair while I sit. I don't know how long it will last if day after day the legs of the chair indent the same location on the mate. I previously had a very thick mate but didn't want to spend 75.00 or better so I'll try this one.
This was perfect for my home office. It is thin enough to still show the carpet underneath - in fact unless you know it's there you don't notice it - yet durable to let my chair roll around on it. It suits my needs perfectly.