Yandex surpassed Microsoft on the number of monthly search queries worldwide in November and December 2012, according to a recently released comScore qSearch report. Microsoft sites processed 4.477 billion queries and Yandex did 4.844 billion.
As you'd expect, Google still reigned supreme with 114.73 billion search queries and a 65.2 percent market share. China search giant Baidu was second globally with 14.5 billion (8.2 percent), and Yahoo came in third with 8.63 billion (4.9 percent).
On closer inspection, the total number of users, worldwide, for Yandex is way below that of Microsoft. It seems that the smaller number of Yandex users are searching more. No doubt they are preferring to use Yandex for the language compatability. That'll be the same with Baidu, i'm sure.
Google, Microsoft and Yahoo are at saturation in their own markets, so it's only a question of exchanging users between one search service or another. It's a little like the competition between the wet shave businesses: They can only steal share from each other.
I'd expect to see both baidu and Yandex search continue to grow as their market's users come online.
Both Microsoft and Google need to grow traffic from each other, or grow in the fast emerging markets of China and Russia.