• by Wendy Davis  @wendyndavis, May 12, 2006

Financial services companies increased their online ad spending last month--purchasing 30 percent of all display impressions, according to Nielsen//NetRatings AdRelevance. One year ago, financial services marketers were responsible for just 20 percent of display ads online; last month, they purchased 28 percent of display ads.

Telecom marketers also upped their online ad spending year-over-year--accounting for 17 percent of impressions last month, up from 12 percent last year. The third-largest category of advertisers--retail goods and services marketers--purchased 15 percent of impressions in April, up from 14 percent in April of 2005.

Spending for Web media--last year the no. 2 category, accounting for 19 percent of online ads--represented 13 percent last month. Within the Web media category, comparison shopping engine NexTag was the single largest spender; that company was responsible for 18.5 percent of ads within the category. Monster Worldwide, Inc., which runs online job site Monster.com, was the second-largest Web media advertiser, with 6.7 percent of all ads in that category.

The overall number of display ad impressions tracked by Nielsen//NetRatings AdRelevance rose to 197 billion last month, up from 185 billion in March. The AdRelevance data doesn't include ads served on proprietary AOL pages, but counts ads that appear on AOL pages accessed via the Web.