Spending on online display ads continues to rise, with more growth expected in the coming years, reports Advertising Age.

Display ad prices will rise by four percent in 2008 and hit $10 billion by 2009. The rise is expected to follow what a "difficult" 2007 for the display ad market.

Last year new inventory was created on social networks and other sites, devaluing existing ad placements as the audience fragmented.

But with spending for presidential campaigns and offline marketers launching online efforts in '08, demand for display ad placement should tighten.

Yahoo is well positioned to take advantage of this demand. The company has spent over $1 billion to improve its display ad network and may effectively monetize both premium and remnant inventory.