The appointment has been confirmed by Twitter, as the popular social networking site looks to build advertising revenue.
It has also confirmed the appointment of Brent Hill as director of sales for the central US region. He was previously at Google where he was head of financial services for the Midwest.
Twitter has been adding commercial services steadily this year, firstly with 'promoted tweets' and then with a new @earlybird account, which gives followers details of special offers.
Dick Costolo, chief operating officer at Twitter, said, "We expect this team to build on our already strong momentum in providing promotions and deals that bring value to both users and an increasing number of brands."
News Corporation announced Bain's departure from Fan yesterday as part of plans to integrate the digital ad network into MySpace.