Mailbox Anchor

According to the Columbia Journalism Review (12/27/12), the US Postal Service is entertaining the idea of selling hard copy magazine subscriptions.  Although magazines make up only a small percentage of mailed items, CJR says that internally the Postal Service calls magazines "the anchor in the mailbox."  The idea is that customers value magazines and, while checking the mail for them, may also take notice of junk mail in the box.  Without magazines, the logic goes, customers may not even check their mailboxes.
http://www.cjr.org/behind_the_news/usps_may_start_selling_mag_sub.php?page=all