Every chef has her favorite knife. Every writer has his favorite character. And every interactive media buyer has her favorite online ad format.

As with other vocations' tools, media buyers' preferred formats have likely alternated over the years. Industry conditions and trends called for upgraded and updated means. New challenges required a different approach. But as sure as you'll get perfectly chiffonaded basil on the pizza at your favorite Italian restaurant or encounter the elusive "Skink" in future Carl Hiaasen books, you'll return time and again to the inspirational instrument that got you started.

In the beginning, my instrument of choice was the plain old square button. It may be unremarkable, but it was the first online buy I ever made. It's gotten me far. I used the little guy to stretch branding budgets and appease clients when in-demand inventory on popular site pages was sold out. I employed both the static and animated variety as publishers and creative concepts demanded and took it from portals to ad networks, e-mail, and beyond.

Since those days, the button has fallen out of favor with other advertisers. They prefer larger, more prominent formats, which studies have shown to be more effective. But in the early, uncluttered days of online advertising, the button was my go-to staple.

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