I have bought several mats like this at the same Staples store over the years. This is the worst one. It was also the cheapest. So no shock there. The last one I bought was the premium one for about double what I paid for this one. It lasted several years and worked much better. This one has had curled edges since day one. Don't buy this product.
The chairmat seems nice. Too bad Staples ruined by sticking their shipping labels right on it... after trying to dissolve the label adhesive for over an hour I gave up and called and complained. Now I have to wait another two days to get another one. Wanna bet the next one comes in the same condition?
This is the second one I bought and I bought it because it claimed it would not creep - but it can creep 4 or 5 inches a day and has to be moved frequently. All of them at Staples seem to use the same thing to hold them in place and they don't work. The old ones did.