Thank you for shopping local. Thank you for shopping locally. Which is correct?

They are both correct, but the two terms are being used to refer to two different concepts.

Thank you for shopping local. This refers to shopping from businesses that are owned by people in your area. Not only are you supporting small businesses, the profits are much more likely to be used in the area.

Thank you for shopping locally. This refers to shopping in your area, as opposed to ordering online. However, this means going to Kmart or Best Buy doesn't help the local area as much, as the bulk of the profits are sent off to the headquarters and doesn't stay in the local area.

It is a subtle difference that is not recognized by many as being different.