Campaigns are “the fastest start-ups in the world,” as Matt McDonald, a former McKinsey consultant who worked on the 2008 John McCain effort and other Republican campaigns, calls them in a new report with that title issued by Hamilton Place Strategies, the Washington public affairs firm where he is a partner. He points out that hot social media companies may attain multibillion-dollar paper valuations quickly but take years to reach a scale equivalent to a major presidential campaign in spending and employee count.

A serious candidate for president, after all, requires a high-functioning team that is built from scratch in just a few months. That typically means appointing a campaign manager who may have a background as a political strategist but who becomes de facto chief executive of a complicated enterprise that has little time to evolve. Start-ups and campaigns are both driven by people with a range of motives: an idealistic desire to change the world along with less noble goals of attaining a great fortune or power.

An enormous staff must be assembled, learn how to work together and execute intricate and interrelated tasks. Among them are raising vast sums of money and developing and executing what is essentially an enormous marketing campaign. In the end, of course, participants hope to persuade millions of people to “buy” — meaning, show up at the polls and vote for the candidate on Election Day.

“A lot of start-ups and a lot of campaigns are similar,” said David Plouffe, the manager of Barack Obama’s 2008 campaign, who is now chief adviser at the fast-growing transportation upstart Uber. “Decisions need to be made, and there are new challenges every day, while at the same time you’re trying to hire a lot of people and scale an organization.”

Ken Mehlman, who headed George W. Bush’s 2004 re-election campaign and is now an executive at the private equity firm Kohlberg Kravis Roberts, sees similar challenges. “I viewed my job as being the C.E.O. of a company that in the beginning was a start-up, and was ultimately a very large company,” he said. “My underlying thesis is that my job wasn’t to be a political genius. My job was to take best management practices and apply them to politics.”