Yahoo’s ranks keep fanning out all over the tech scene.

This time it is former top-ranking Yahoo exec Jeff McCombs (pictured here), who has signed on to be CFO of Tumri, an online advertising start-up.

Backed by Accel Partners and others, the Mountain View, Calif.-based Tumri is trying to crack into the online ad space with what it calls “dynamic and intelligent display advertising solutions.”

Essentially, using a product called AdPod, that means display ads that are delivered more easily and automatically with a relevant marketing message, depending on the consumer.

McCombs, 37, is a big hire for a small company like Tumri. He was SVP of Business Operations at Yahoo (YHOO).

At Tumri, he will be managing all financial activities, including financial planning and analysis, accounting, investor relations and corporate development. He will also be responsible for overseeing business development, human resources and legal.

Said Calvin Lui, Tumri president and CEO: “Jeff’s wide spectrum of experience will be instrumental in helping guide our explosive growth and will help solidify our innovation and leadership position. We are excited that Tumri’s transformative mission is attracting this high caliber of talent.”

Indeed, at Yahoo, McCombs had also served as chief of staff to former president, Sue Decker.

Previous to that, he worked at a number of investment banking, corporate development and private equity firms.

As CFO, McCombs will also be a key exec at Tumri, said Lui, helping steer its strategy.

“Making display ads performs better is the next great opportunity,” said McCombs, in an interview yesterday, noting that the sector needs to have similar ability to measure effectiveness as search ads do. “You need to be able to completely understand why one ad performs better than another online.”