Years ago i would've thought they were just a fad, but a freind that used to be on the massage therapy staff of the Colorado Ride the Rockies used to bring me some of the free swag she used to get, including several; pairs of DeFeet cool max socks, that I still wear, years later. Here in south Georgia, i get home from a ride my jersey is completely saturated, but my feet are largely dry. When i wear cotton socks this time of year, for walking, or even for non athletic stuff, they are noticably damp when i pull them off.
I HIGHLY recommend some decent bike-specific socks.
That being said, i tried them when out walking, and being thinner and a little rougher, I found them uncomfortable after a couple miles, and prefer my thicker, cotton, ankle-length socks. Go figure.

P.S. I've tried Walmart cotton socks, and found them to be junk. But, I'm getting GREAT longevity out of the shorty Burlington socks from Sam's Club (oddly, the longer ones haven;t been is solid.)