Date: 27th November 2000
The U.S. Postal Service has begun canceling holiday mail with a postmark reading "Happy Wholidays," a reference to the residents of Whoville in Dr. Suess's How the Grinch Stole Christmas, according to Advertising Age.
The postmark -- the very first to promote a commercial product nationally, according to the trade publication -- is reportedly part of a general cross promotion involving the Grinch movie, embracing the USPS, Universal, and Imagine Entertainment. No money changed hands, according to the Ad Age report.
Source: Studio Briefing