Bijan Sabet of Spark Capital and Jeff Bezos of Amazon.com, Inc. (NASDAQ:AMZN) have announced that they have joined Twitter’s Board. It was not revealed before today that Jeff Bezos was an investor in Twitter’s rumored $15 million third round of funding [GigaOm].

“Existing partners Union Square Ventures in New York City and Tokyo-based Digital Garage exercised their pro rata rights to participate in this round as well,” wrote Twitter founder, Evan Williams on the Twitter blog.

Twitter chose Bijan because he is a man that understands the direction of Twitter.  Bijan is “super excited about the possibilities.”  Bezos was selected because he is a seasoned veteran and because he is a source of inspiration for Twitter.

“Jeff’s attention to business process details and distinctive, ‘honk-like laugh’ are similarly admirable traits as far as we’re concerned,” added Williams.