• by Wendy Davis  @wendyndavis, January 15, 2007

E-mail sites claimed just 44.2% of online display ads last month--down from November's 47.5% and October's 51.1%, according to new data by Nielsen//NetRatings AdRelevance.

Yahoo's e-mail service drew 36.4% of ads last month--also down from November's 40.4% and October's 43.6%. MSN Hotmail captured 6.4% of ads, up slightly from November's 5.7% and almost flat from October's 6.3%.

Overall, online advertisers ran 257.7 billion display ads last month, compared to 259.6 billion in November.

The measurement company also reported that financial services marketers stepped up their Internet efforts last month, accounting for 29% of the online display ads--up from 25% in November. Web media accounted for the second-largest category, with 17% of impressions--down from 20% in November. Retail goods and services accounted for 16% of impressions, flat from November; telecoms accounted for 13%, up from 10% in November. Rounding out the top five categories was public services, with 6%, down from November's 9%.

Nielsen//NetRatings AdRelevance does not track certain types of online advertising, including pre-roll, partnerships, and sponsorships. The AdRelevance data also doesn't include ads served on proprietary AOL pages, but counts ads that appear on AOL pages accessed via the Web.