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
If you speak a second or third language, you may remember the first time you dreamed in that new tongue. But does this milestone mean you’re actually fluent? And a couple’s dispute over the word regret: Say you wish you’d been able...
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...