It's not a real letter. It's an updating of an older piece of Internet humor that goes back to at least 1997, variously titled "Things to do in WalMart while you shop," "How to handle stress," and "While waiting for your wife at Wal-Mart":
Things to do at Wal-Mart while your family is taking forever to finish shopping.

fake letter... stupid news editor taking things seriously from the internet... wakakaka