Counterclockwise is an anti-pattern (at least for me), my guess is that it makes shoppers move more slowly, pay more attention to displayed items and spend more time at the shop.
Right-handed people, with their bias toward turning right, tend to walk anti-clockwise when entering a loop from the outside (such as grocery stores), and clockwise when entering from the inside.
People who travel anti-clockwise see more stuff, because if they travel clockwise, then they'll turn right and toward the front/exit before they finish a complete loop around the store.
