Yahoo Still King Of Display Advertising

Yahoo is farming out its search business to Microsoft to focus on display advertising. That's probably the right idea, as Yahoo is still the largest display-ad publisher in the industry, by a considerable margin.

Yahoo delivered 521 billion ad impressions in the 12-month period ending last November, according to comScore, beating out Fox Interactive (including MySpace) at 368 billion and Facebook at 330 billion.

And things finally seem to be picking up: During Yahoo's Q4 earnings call, CEO Carol Bartz said display ad revenue grew 26% from Q3. That was the strongest sequential growth the company had seen since 2006.

To stay on top, Yahoo will have to keep traffic to its homepage portal strong -- which could mean a major upgrade to its Mail service -- and fend off rising players like Facebook and AOL.