Classic Lines Like a good novel, your slogan needs substance if you expect it to stand the test of time and move your product out the door.

This is my once-a-year homage to what may be the best advertising slogan ever written. If you're a regular reader, maybe you know of my fawning, practically idolatrous affection for the original catch phrase of national bookseller Crown Books: "If you paid full price, you didn't buy it at Crown Books." You may have your own favorite slogan, but this is mine, and I'll tell you why.

Slogans are typically self-indulgent afterthoughts that have little substance. This is a shame, because like the P.S. on a letter, they virtually always get read. When I was growing up, the hot slogans were G.E.'s "Progress is our most important product" and Zenith's "The quality goes in before the name goes on." Both are cleverly crafted, but like nine-tenths of the slogans written today, they're all out of steam and don't pass my acid test for a great slogan: Can it stand by itself in selling your product?

If you're thinking the Crown Books slogan doesn't have much bite anymore either, you're right. It lost at least 75 percent of its teeth during the decade or so that nearly every other bookstore chain in America followed in its discounting footsteps. But when Crown first came on the scene, it had the discount-starved book-buying public virtually all to itself. So the message, with its smartly crafted wording, was, to me, advertising dynamite and deserving of some sort of brass plaque in the Copywriter's Hall of Fame. In my opinion, no company has ever had a harder-working slogan.