Or reasons obvious to the Twitter historians and superfans, anyway: In a blog post yesterday, Twitter co-founder and Stoli Vodka shill Biz Stone announced he'll be getting "out of the way" of Twitter's current staff to relaunch Obvious Corp, the company that originally sat on Twitter until it warmed up enough to hatch and become the adorable little chick we know today. Obvious' goals aren't so... well, obvious — in their mission statement, the company says Obvious "makes systems that help people work together to improve the world." So, another well-meaning, somewhat nebulous Silicon Valley startup, basically.

Biz mentions he'll stick around if the Twitsters need him when they move to their new, stock option tax-free home on Market Street, but he'll mostly be focusing on charitable efforts, nonprofits and company advisory boards. And speaking of non-profits, current Twitter CEO Dick Costolo still has to figure out how to make some real money off of the service. Their current advertising revenue is only expected to bring in $150 million this year, hardly enough to cover operating costs.

[AP/Examiner]