Most of the political ad buys may still be going to print and TV, but Yahoo! seems to have captured the lion's share of campaign ad dollars spent online.

According to a ClickZ story, Yahoo snagged 32 percent of political advertising on the web, serving 90 million ad impressions. MSN came in second with 30 million impressions, totaling 11 percent of display ads run in connection to the various campaigns.

While MySpace and Facebook have been touted as vital tools for many campaigns, neither site factored heavily in the display ad business.

Based on numbers reported by Nielsen Online's AdRelevance unit, Gov. Mitt Romney bought the most impressions -- 103 million. Sen. John McCain came in a close second, buying a little more than 94 million impressions in 2007. Sen. Barack Obama led all Democrats with 75 million impressions.