The favorite downtime-riddled platform for sharing the lumps life gives you in 140 characters or less, Twitter, has received a hot investment infusion of an undisclosed amount from Amazon founder and CEO Jeff Bezos and Bijan Sabet of Spark Capital. Spokesperson Biz Stone promises everyone that "Twitter will become a sustainable business supported by a revenue model," though they must have been a bit more specific when pitching to Bezos and Sabet. Sabet, for his part, earned himself a seat on Twitter's board with the deal. [Twitter Blog]