Washington: The billionaire running for president now seeks to convince millions of Americans to give him money.
With the simple tap of the "send" button one day last week, Donald Trump collected USD 3 million in campaign contributions as much as he did in the entire month of May.
He had asked for donations of USD 10 or more, with the promise of chipping in USD 2 million of his own money to match those that arrived.
That one-day haul from Trump's first fundraising appeal is early evidence of the digital magic it takes to fill campaign coffers Bernie Sanders-style millions of people, each giving a few bucks.
Yet that was just one email. Success demands repetition.
The presumptive Republican nominee must now make the case that he needs money, after months of boasting that he can pay his own way. And his campaign also is failing in what could be called "the art of the email." One analysis found that 74 per cent of his first fundraising requests landed in spam folders.
Still, if Trump can reap millions of dollars from each pitch, that could help him solve an urgent problem: He's being crushed by Democratic rival Hillary Clinton's well-honed finance machine, which pulled in 10 times as much as he did last month.
Campaign money pays for the advertising and employees needed to find, persuade and turn out voters on Election Day.
Trump's national finance chairman Steven Mnuchin said the campaign was "overwhelmed" by reaction to the first online fundraising appeal. "This is now going to become a daily effort," Mnuchin said.
Since that initial email, the Trump campaign has sent at least four more solicitations, including one yesterday from chief strategist Paul Manafort touting the fundraising success of the week and urging supporters to keep up the momentum.
Trump's partnership with the Republican National Committee also pays special attention to the small donors who typically give online.
They have a joint account called the Trump Make America Great Again Committee that has sent two dozen emails in the past month.
"Contribute $100, $50, or even just $25 to show you're ready to keep winning!" one missive asks. Each donation is divided, with 80 per cent going to the Trump campaign and 20 per cent to the RNC.