Update June 25, 2017: Finally had a heel in one sock blowout. So a little over 9 months for that to happen. All the other socks are still in good shape though. I am beyond impressed by these socks.
Let me say up front that I am a UPS Driver and am on my feet for 10-12 hours a day. I blow through socks in weeks sometimes. That is why I have been searching for socks that could take a beating and yet be comfortable. These socks are hands down the best socks I have ever owned in my life. They are tight but not overly tight. More of a compression sock feel that gives greatly needed support. They are warm without making your feet sweat. Best of all they last and stay in great shape even 5 months later. Which for me and my job is quite impressive. I will never buy another type of sock again. Got these beginning of September 2016, coming up on the beginning of February now and they are still in excellent shape. Two things that would normally cause all previous socks to start to fail and rip are my tough heels that can get quite callused. This would result in a blowout in the heel of the sock. The other thing was sometimes untrimmed toenails would catch the inner fabric and cause a small run that would ultimately lead to the toes failing. Neither of these things has happened to these wonderful socks. I can't say how happy I have been with these. Highly recommended.