We still don't know which half

144 years ago, John Wanamaker revolutionized marketing. He built America's first department store and pioneered the price tag for merchandise. He invented the money-back guarantee and hired the first full-time copywriter.

But he's most famous for saying, "Half the money I spend on advertising is wasted; the trouble is I don't know which half."

What's crazy is that we still argue and disagree about how advertising works, how brands work, and how shoppers work.

So to paraphrase Wanamaker, half the ideas we have about advertising are wrong; the trouble is we don’t know which half.

However, there are answers. The science exists. But it's hidden like a buried treasure, waiting to be used by those willing to challenge their own beliefs and follow where the facts lead us.