Apparently, due to state prohibition laws calling for retailers to “serve the public need,” anyone (in certain states) can walk into Costco or Sam’s Club and buy liquor, beer or wine without having to fork over for membership fees. Here’s a clip from an article on this loophole courtesy of Smart Money:

Thanks to some little-known state laws, nonmembers can purchase alcohol without paying a membership fee. These laws date back to the 1930s, when Prohibition was repealed. Massachusetts’ law, for example, provides that applicants for a license to sell alcohol must “serve the public need and protect the common good.” In simpler terms, alcohol sold must be available for purchase by the greater public — no membership restrictions.

The article also cautions that most store employees and managers may not know about the law, and to print out the article and show it to them if they get in your cheese. To me the legal basis for this move seems a little thin, but if you’re able to pull it off, more power to you.