mailbox money
n.— «The recurring revenue SCR earns as a result of switching its clients to Mercury is what Milligan refers to as “mailbox money.” That is, once a client is switched over, SCR receives a monthly residual check from Mercury based on the card processing activity of the customer. All Milligan has to do is walk to the mailbox.» —“3 Steps to Increased POS Sales” by Mike Monocello Business Solutions Aug., 2007. (source: Double-Tongued Dictionary)
Further reading
While reading Great Expectations (Bookshop|Amazon) by Charles Dickens, a listener in Arlington, Texas, is surprised when one of the characters inherits some money, which Dickens describes as a cool four thousand. Were they really using cool that way...
Among the proverbs in Leo Rosten’s Treasury of Jewish Quotations (Amazon): If you drop gold and books, pick up the books first, then the gold. This is part of a complete episode. Transcript of “Who Is Just Carrying Around Gold, Anyway?” Here’s a...