Taking a cue from Kara Swisher of All Things Digital, we’ll focus on two respective properties of Microsoft and Yahoo: their webmail services. Yahoo Mail and Windows Live Hotmail. The two biggest whales of the industry. No other contenders come close. Yahoo has an edge, at 256 million users, to Microsoft’s 255m, but they’re virtually at a dead heat. They’re equals, more or less. Gmail and AOL Mail trail at some 92m and 49m, respectively.