They're creepy and more than a little annoying, but there's a reason retargeted ads are gaining steam: They work.
Bother people enough and not only will they notice what you're saying, they'll remember it four weeks later and search the product online. At least, that's the operative lesson from a recent ComScore study that measured a number of different targeting strategies.
Based on 100 campaigns running July 2009 through March 2010, which were delivered by Value Click Media. Source: comScore
A retargeted display ad will encourage 1,000% more people to search for a product than a standard ad, according to the study. That tactic worked twice as well as buying audiences, an increasingly contentious practice as politicians look to draft legislation to protect people's privacy online. Interestingly, buying placements on premium sites was the third-best-performing option.
To be sure, brand-focused advertisers will want nothing to do with retargeting -- or will they? The numbers are appealing.