Yahoo! ad-share gaining ground on Google?

New industry data out this week shows Yahoo! may have started gaining share in the web-search ad market against Google, even as Google's share of search audience inched up.

One study by RBC Capital using data on ad-buying trends from web-search marketing firm SearchIgnite shows Yahoo! outpacing Google in spending on search advertising, ad viewer-ship and click-through rates during the first quarter.

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Meanwhile, a report by Citigroup using data from research firm comScore showed Google gaining share against Yahoo! in the overall web-search market in March - but gave no insight into how Google is doing converting web searchers into ad viewers.

Yahoo!'s first-quarter share of search spending by selected advertisers rose to 23 per cent of the market, up from historic levels of 18 per cent to 19 per cent, SearchIgnite said. Google's dominant search advertising share dipped to 71.1 per cent from 74.9 per cent the previous quarter.

Referring to the SearchIgnite data, RBC analyst Ross Sandler said in a note to investors: "Yahoo! increased its share of wallet meaningfully for the first time in several quarters."

Google is set to report quarterly results on Thursday as investors debate whether the company's explosive growth in search advertising has begun being hobbled by a slowing economy. Yahoo! reports quarterly results next Tuesday.

Yahoo! is conducting a two-week test of whether to use Google's system to sell web-search ads instead of its own. Yahoo! has been seeking partners to help it fend off a takeover by Microsoft, or at least force a higher bid.