Upon carefully examination, it was found to be an expensively produced direct mail advertising flyer. The union printer's imprimatur in tiny print was the only thing that gave it away.
I’ve seen a number of those- probably political ads or car dealer ads are the most common here. Junk mail is my nemesis. Someday, I swear I’m going to put some kind of a trash container right next to the mailbox so that it never makes it into the house.