• by Mark Walsh  @markfwal, December 16, 2009

If the 25- to-54-year-old demographic is the sweet spot for online video advertisers, they may need to aim a little lower. Kids under 14 are generating the highest click-through rate on pre-roll ads, at 3.7%, according to the latest user data from video ad network YuMe.

That group's parents -- people over 35 -- had the next-highest CTR, at 1.9%, followed by those 18 to 24 at 1.5%. For any age group, the pre-roll remains by far the dominant video ad format, accounting for 96% of ads served through the first nine months of 2009. During that period, the pre-roll actually gained ground at the expense of overlay ads -- which dropped to 3.4% in the third quarter, from 10.5% in the first quarter.

Within the pre-roll format, 15-second spots accounted for 65% of ad volume, with 30-second units making up the balance. Not surprisingly, the shorter ads had a higher completion rate, at 77% compared to 64% for :30 spots. But the longer ads had a higher CTR, at 1.8% versus 1.2%.

Overall completion rates dropped to 67% in the third quarter from 74% in the first quarter, partly as a result of an increase in :30 pre-rolls on the YuMe network, which has served 3 billion impressions this year through November.

Among marketer categories, household goods companies led the way in video advertising, with a 17% share of spending, followed by autos (14%), beauty products (12%), food (8.6%) and entertainment (7.3%).

YuMe's network encompasses 500 Web publishers including msnbc.com, NBC, and Glam Media and has advertisers such as Ford, Research in Motion (BlackBerry) and Target. It reaches some 63 million unique visitors monthly.