Danny Sullivan at Search Engine Land analyzes a Compete.com report that shows MSN Search (aka Windows Live Search) gaining market share, "jumping from 8.4 percent in May 2007 to 13.2 percent in June."
Danny and a follow-up post from Steve Willis at Compete.com both credit the gain to a marketing promotion Microsoft is running called Live Search Club that apparently involves executing many searches as part of playing games and winning prizes. Both note that MSN Search share was only 9.1 percent -- a modest gain if not flat -- if you exclude all the Live Search Club searches.
Even if this is all from Live Search Club, I am surprised. I would not have thought a promotion like that could result in this much of a gain. I also would doubt such a gain can be sustained much beyond the duration of the promotion, but it is a trend worth watching.
See also my Nov 2006 post, "Google dominates, MSN Search sinks".
Update: Looks like at least part of those gains from that promotion were temporary. Two months later, Todd Bishop reports Live Search market share has dropped in July and August.