Sarah McBride and Alexei Oreskovic:

>Costolo said the company counts roughly 600 advertisers, up from 150 advertisers at the end of 2010.

and:

>The company is expected to bring in about $150 million in ad revenue this year […]

Do take note that in December they *raised* 200 million dollars in VC money, yet they are set to make *only* 150 million of that back this year. Add to that the fact that they had 450 less advertisers last year and it makes this last statement even more comical:

>Costolo declined to answer a question about whether Twitter was profitable.