• by Wendy Davis  @wendyndavis, December 15, 2005

Marketers served 115.2 billion display impressions online last month--down about 7 percent from the 124.5 billion served in October, according to new data from Nielsen//NetRatings' AdRelevance. Still, more impressions were served in November than every other month from March through September.

E-mail sites accounted for the largest proportion--26.7 percent--of impressions, up from 20.8 percent last November. Portals and search engines garnered 12.3 percent of ad impressions--down slightly from 15.5 percent last year--while general community sites took in 11.5 percent of impressions, up from just 4.8 percent in November of 2004.

Specifically, Yahoo! Mail accounted for the largest share of ads--16.7 percent--while social networking site Myspace took in 7.9 percent and MSN Hotmail served 6.7 percent of impressions. One year ago, MSN Hotmail was the market leader, with 8.8 percent, followed by Yahoo! Mail at 7.6 percent and Yahoo! Finance with 3.5 percent.

Financial services advertisers were again the heaviest online marketers, accounting for 20 percent of impressions last month, which was flat from November of 2004. Telecoms were responsible for 19 percent of online ads, more than double last year's 9 percent. Web media accounted for 16 percent--up slightly from last year's 15 percent.

Nielsen//NetRatings also looked at impressions just within the hardware and electronics category--which accounted for about 4 percent of all display ads in November. Dell Computer Corporation was far and away the largest advertiser, accounting for 49.6 percent of all ads within that category--which is about the same as last year's 48.1 percent. Hewlett-Packard was responsible for 7.6 percent--a slight drop from last year's 8.5 percent--and Toshiba Corporation placed 6.4 percent, compared to 5.4 percent last year.

Nielsen//NetRatings' AdRelevance doesn't include in the data ads served on proprietary America Online pages, accessed only by AOL subscribers--but counts ads that appear on AOL pages accessed via the Web.

Online Display Impressions March--November 2005

Month	Impressions Served (bil)
March	97.1
April	91.4
May	93.1
June	97.1
July	102.9
August	112.1
September	110.2
October	124.5
November	115.2

Source: Nielsen//NetRatings AdRelevance