Bloomberg spent $1 billion on 104-day presidential campaign

Former New York City Mayor Mike Bloomberg spent more than $1 billion during his Democratic presidential campaign that lasted for 104 days — including $176 million in March, a filing to the Federal Election Commission Monday shows.

The big picture: Bloomberg won 55 delegates and one contest in the primary, in American Samoa, after paying out about $18 million per delegate. He spent over $580 million on advertising and a campaign operation of 2,400 staff in 43 states from his November launch to his campaign suspension in March. He paid $23.3 million in salary, fees, payroll taxes and fringe benefits. Some former staffers filed a lawsuit after he reneged on a vow to pay them through November, even if he weren't the nominee.

Go deeper: Letter from Planet Bloomberg