I’ve been advertising online for well over a decade. I’ve written hundreds of articles, spent thousands of hours talking to companies about online marketing, and overseen more than a billion dollars in marketing spend with everyone from mom-n-pop shops to such brands as Red Lobster,, and Encyclopedia Britannica.

Over the years, I’ve watched performance marketers dismiss display advertising as a too-expensive-time-wasting-useless inventory source. These marketers have made a mistake and missed one of the largest growth areas in effective online advertising that exists.

Years ago this was the correct decision—but not any longer.

When I started advertising online in 1998, banners were the preferred ad format. These banners ...

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