Consumers tend to wait about 21 seconds before shutting off 30-second online ads, according to estiamtes released Tuesday by Klipmart Corp. The online video services company examined about half a
billion 30-second video ad impressions that ran on around 200 Web sites in the first six months of this year. The ads all ran in banner units, and most of them played automatically when users opened
the page. -- Wendy Davis
