Search Uplifts Conversion Rates of Display Ads - duh!!
Another study that shows search ads (yes, plain ole boring text-based ads) uplift sales help increase sales of people who click on banner ads. "A new study (pdf) from Atlas Institute found a 22 percent increase in conversions when users were exposed to an advertiser's search as well as display ads, rather than only to the search ad, reports ClickZ. ... Those exposed to search ads alone converted at three times the rate as those exposed to only display ads."