• by Mark Walsh  @markfwal, November 16, 2009

Right Media Exchange founder Michael Walrath, who sold the company to Yahoo for $680 million in 2007, is the latest top executive to exit the Web portal.

Walrath, whose most recent title at Yahoo was senior vice president of advertising strategy, told The Wall Street Journal in an interview that it was the "right time to move on in my career," and said he planned to spend time working with small innovative companies.

The move comes as Yahoo is repositioning its Right Media Exchange to agencies and ad networks as a "premium exchange" so it's not perceived as a platform only for trading unsold inventory. To that end, Yahoo will start drawing online publishers such as Ziff Davis to the exchange and boot lower quality ad networks that aren't adding value by overlaying data or providing advanced targeting, according to an Advertising Age story Monday.

The advertising community wants an upscale, high-quality marketplace where audiences can be bought at scale, and in real-time. Yahoo and Right Media have been at the forefront of this shift and we will continue to leverage the Exchange to capitalize on this trend," wrote Bill Wise, senior vice president for platforms at Yahoo, in a post Monday on the Right Media blog. Yahoo also wants to work more closely with agencies as they increasingly turn to public exchanges to buy highly targeted audiences.

Right Media was one of the first ad exchanges, creating an online market where display advertising could be traded through a bidding process similar to search advertising. But the Yahoo unit faces growing competition, especially from Google, which recently relaunched the DoubleClick Ad Exchange that offers access to all its AdSense inventory. Right Media's biggest client is Yahoo, which sells all of its "non-guaranteed" display inventory (inventory not pegged to particular content at a specific time) through the exchange. Wise considers the type of inventory Yahoo sells into the ad portal to be a model for other companies.