Fundraising plays a central role in many presidential campaigns, and is a key factor (others include endorsements/messaging/visits/staffers) in determining the viability of candidates. Money raised is applied for the salaries of non-volunteers in the campaign, transportation, campaign materials, media advertisements and other contingencies. Under United States law, officially declared candidates are required to file campaign finance details with the Federal Elections Commission (FEC) at the end of every calendar month or quarter. Summaries of these reports are made available to the public shortly thereafter, revealing the relative financial situations of all the campaigns.