Let’s try this out and see what the reaction is. This cliché, alluding to raising an actual flag up a mast or flagpole, is one of a number of phrases coined in the mid-1900s in the Madison Avenue advertising industry for trying out ads, campaigns, slogans, and the like. Another is that’s how the cookie crumbles. The New Statesman so identified it on March 25, 1966: “The decision was made—in the admen’s jargon that comes naturally to Tory strategists—to run it up the flagpole and see if anyone saluted.” It may be dying out, replaced by the simpler run it by/ past someone. For example, “Bill wanted me to run his new plan by you and see what you think of it,” or “You’d better run it by the teacher before you order any supplies.”