Classic LinesLike 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?