In the six months since Microsoft launched Bing, the search engines share of the market has inched up from 8 to 9.9 percent, according to comScore. So where’s this uptick coming from?

At the Credit Suisse Annual Technology Conference, Microsoft SVP Yusuf Mehdi said the company was enjoying success winning over younger searchers. He said that with Bing Microsoft had improved its performance with the critical 18-to-24-year-old demographic, which he said makes up a disproportionate number of the search engine’s users. By contrast, Mehdi said that Live Search was “over-indexed” with the 65-year-old-plus age group.

No surprises on the latter nugget.

Mehdi said that Microsoft believed that next year searches on mobile phones will begin to take market share away from searches on PCs; in response, he said that Microsoft was planning “clients” for the iPhone, RIM, and other platforms. He also downplayed reports that Microsoft is in discussions with news publishers to pay them to pull their content from Google, saying that the company’s “focus (is) on improving the user experience, not to pay people to deindex (from) our competition.”

We’ll keep you apprised of developments as they arise.