People can open the bag, feel the contents, then reseal it. So when you buy your (potentially fondled) socks, you can have more confidence that none just fell out of the bag. Really this is saying "yes, you can
feel the material that these are made of and no one will mind". Same concept as toys with a "try me" button sticking out of the packaging.
Of course, some could be stolen. But if someone has reached the point of stealing individual socks...
Originally posted by: GodlessAstronomer
I've never seen socks in a resealable bag
Then you've never bought Hanes or Fruit of the Loom (or many of their competitors) socks. Socks that are sold in bigger packages (3 pairs or whatever) seem to do this, socks sold in single pairs seem to not do it.