Presidential campaign money comes from a combination of fundraising and the Super PAC, a specialized political action committee. Large donations to the Super PAC are most likely to come from wealthy individuals; in 2012, the largest donations came from people who worked in finance.
Political campaigns can also receive money through individual donations, taxpayers and dark money. The latter refers to money with unknown sources, though some of these have been revealed to be nonprofits and social welfare organizations exploiting a legal loophole that allows them to hide the names of individual donors.
The Super PACs appeared in 2010 following a Supreme Court ruling that determined that the federal government was unable to prevent corporations from spending money to influence elections. Super PACs cannot directly donate money to candidates, but they can solicit donations and choose a candidate to support instead. Unlike the donors in dark money, however, the donors of a Super PAC have their donations reported to the Federal Election Commission.
An estimated average of $1 billion is needed to run for president. During the 2012 election, almost half the money raised was spent on advertising, followed by administrative costs. Campaign expenses are the third largest cost, followed by loan payments, refunds, parties and miscellaneous expenses.