NEW YORK: A formula that would exorcize TV moguls' and marketers' most feared phantom - ad skipping via digital video recorders - could be disinterred from the dust of one hundred and seven years.

Fast-backward to 1900, when US psychology professor Knight Dunlap flashed an imperceptible shadow to subjects while showing them the so-called Müller-Lyer illusion. He claimed the shadow unconsciously influenced his subjects in their judgment of the lengths of the lines.

[Stare for a moment at the the graphic above and you'll see something similar.]

Now fast-forward to 1957 when market researcher James Vicary discovered that that quickly flashing messages on a movie screen motivated people to purchase more food and drinks. Presto! The term 'subliminal advertising' was born.

And within a decade forgotten.

Keep your finger on the >> button to August 2007, when NBC Universal measured the effectiveness of TV ads that viewers skipped-through via their DVRs.

Much to the surprise (and delight) of NBC's nabobs, viewers still recalled the ads – or certain segments of them – despite watching at up to six times normal viewing speed.

Moreover, viewers were more likely to remember an ad in fast-forward mode if they'd previously seen it in normal motion. Familiarity with logos or brand characters also helps recall.

For example: a Mucinex ad featuring Mr Mucus, a cartoon  brand spokesman in the guise of an animated blob of phlegm, scored particularly well in NBC's fast-forward tests

As did a 30-second trailer for the third instalment of the Bourne movie franchise. This earned high recall scores because many viewers were already familiar with the film series and its star Matt Damon

So, how best to exploit the 'subliminal' effect?

Some advertisers are planning to launch new campaigns during live events like sports games and then re-run the spots during programs likely to be recorded.

And according to OMD's global research director Mike Hess, marketers may also choose to test multiple edits of a commercial to see how it performs when fast-forwarded.

"I don't think the industry is about to create a whole round of commercial around DVR viewing", he says. "But if you're sensitive to that, there are some things that you can try to do better."

John Mossawir, svp of research at Initiative Media is in accord. "It shows that the mind starts to take short cuts in fast motion."

The NBC study also proves that simple, traditional plotlines perform best in fast-forward. "Having things come in at weird angles, tricks with pacing don't work there," says Mossawir.  

The study was conducted in August 2007 with a sample of one hundred people in the 25-35 age group, who watched twenty-four ads during the pilot of NBC's show Journeyman. Most of the ads used in the test had already been aired.

The responses of viewers who watched the ads live were then compared with with the responses of those who fast-forwarded through them.

Data sourced from Wall Street Journal Online; additional content by WARC staff