Smartwool, which claims to have led the “Merino wool revolution,” is celebrating its 20th anniversary this year. Since 1994, the company has sold more than 80 million pairs of socks and tens of thousands of apparel products, made with proprietary technologies, through 5,000 retail stores in North America and many others in 37 other countries around the world. Smartwool, which entered the performance run category in 2012, says it has the top-selling performance sock in the ski, snowboard and outdoor categories.