Online sources are reporting that the company had been losing money at least till the first quarter of the 2011.
Some financial reports have been leaked. Things should be better for the company today as they have been doing well with their advertising services like Promoted Tweets and Promoted Accounts.
The reports said that the company made losses of around USD 25.8 million in the first three months of 2011.
Things were worse in 2010 when they made losses of USD 67.8 million.
Twitter is not a public company so we usually do not get to see these figures. We hope that things are going well for them and they are finally generating some profits. Though it would be hard to confirm that.