This tactic hasn’t been limited to bids for higher office. Political protests have also used such services to fortify its crowds: The New York Times reported that, during this year’s NYC Pride Parade, a group of anti-gay marriage “protesters” were actually several hired day laborers. Local carpenters unions—notably the Mid-Atlantic Regional Council of Carpenters—have been using such tactics for years, paying temporary workers (and often the homeless) to walk picket lines during a strike.

These days, if a candidate or protest organizer is short on numbers, he or she can simply pick up the phone and call a company like Crowds on Demand, a Los Angeles–based company that provides rental crowds for campaign rallies and protests. The company was founded in late 2012 by Adam Swart, a UCLA grad who majored in political science. It is among a very small number of companies that offers rental crowd services in the U.S. (including Crowds for Rent and the Trump-hired Extra Mile Casting), and perhaps the only one that does so openly.

While Crowds on Demand was initially geared toward corporate events and PR stunts, Swart says that soon after the company’s founding, would-be elected officials began reaching out for his services in order to give their campaigns a boost. Some have used his services to protest opposing candidates; others have used them to create the appearance of larger turnouts at their own events.

“Our business is about cultivating perception. It’s basic marketing,” Swart said.

Outside of the realm of politics, Crowds on Demand offers an array of crowd-providing services, ranging from a “celebrity shopping experience”—the client mobbed by fake paparazzi outside a posh L.A. boutique—to big PR stunts, such as a 100-person flash mob at a corporate trade show. Swart says his gigs have ranged from two people to hundreds, and that with enough notice (and money) Crowds on Demand can offer more than 1,000 people. But whether the setting is a campaign rally or a convention hall, Crowds on Demand’s goal is always the same: getting people’s attention.

Crowds on Demand offers its services in San Francisco, New York City, and Washington, D.C. Thousands of people have applied to be extras with Crowds on Demand. Swart says that he has the most “crowd actors” in cities where real actors tend to try to make it—New York and L.A.—but he has actors available in political hot spots such as Iowa and New Hampshire as well. And while his company generally works in more populous areas, it isn’t limited by geography—or ideology for that matter.

“We’re not a Republican or Democratic group, so we’ll work with both. And third parties,” Swart said, adding that Crowds on Demand’s one major prohibition is against working with hate groups.

While Swart declined to discuss which candidates Crowds on Demand has worked for, the company’s fingerprints have occasionally been spotted. Campaign-finance filings in California show that Crowds on Demand was paid more than $50,000 by the “Six Californias” campaign, a failed ballot initiative funded by Silicon Valley venture capitalist Tim Draper to split the Golden State into six independent states. The New York Post also found that scandalized former congressman Anthony Weiner paid Crowds on Demand actors $15 an hour to turn out for events during his bid for mayor of New York City in 2013.