Donald Trump likely left tens of millions of dollars on the table by essentially ignoring online fundraising until recently, experts in both parties say, a decision that could have lingering consequences for his financially outgunned campaign in November.
Small-dollar online donations have become a key revenue source for modern presidential campaigns. And grassroots funding seems particularly well-suited for Trump, who has faced resistance from traditional GOP donors on one hand, while galvanizing a populist movement on the other.
Instead, Trump's campaign finished last month with a paltry $1.3 million in the bank, allowing Hillary Clinton and her allies to outspend her rival $26 million to $0 on battleground states airwaves.
The Trump campaign will likely end this month in much better shape. The Republican National Committee has now taken over Trump's email marketing, via its joint fundraising committee with the campaign, according to an official familiar with the matter. And the campaign has touted promising results after sending its first email solicitation last week, along with more traditional in-person fundraisers.
But Trump's hesitation to pay attention to fundraising and professionalize his operation -- he abruptly parted ways with a top digital adviser Thursday -- will likely continue to cost him in lost revenue for the rest of the election, according to operatives involved in online fundraising.
"It's professional malpractice," said Erin Hill, the executive director of Act Blue, a digital clearinghouse that powers online fundraising for most top Democratic candidates, of Trump's lack of efforts on online fundraising.
"The trump campaign thinks that in June of an election year they can just turn that on like a spigot, and frankly that's offensive," said Hill. "They've mostly been selling people hats, and treating them as consumers, not as partners."
Trump has shown little interest in raising campaign cash, which he could afford to ignore while self-funding his primary campaign. "First of all, I don't even know why I need so much money. You know, I go around, I make speeches, I talk to reporters -- I don't even need commercials," Trump said while campaigning in Maine Wednesday.
But the billionaire has decided he's unable or unwilling to fund his general election bid himself, so Trump will have to raise money from somewhere. A natural choice would be for Trump to take a page from Bernie Sanders, who praised his army of small donors as proof he was not beholden to special interest.
"He's the kind of guy who does better by getting the pissed off grannies to send him $20 out of her Social Security check every month," said Liz Mair, a Republican online strategist, who has been critical of Trump. "But he hasn't been anywhere close to as concerted about it to date as he should be for a candidate who has his message, his vulnerabilities and his profile."
Meanwhile, Trump's campaign abruptly parted ways with a top-level digital strategist Thursday. And only a portion of the money raised by joint fundraising committees goes to the Trump campaign itself, with the rest going to the RNC.
While it's impossible to say precisely how much Trump could have raised with an earlier start and more sophisticated operation, half a dozen Republican and Democratic operatives contacted by NBC News agreed it's safe to guess the number is eight figures.
One veteran Republican strategist, who spoke on the condition of anonymity out of fear of retribution from his party's presumptive nominee, estimated that Trump should have raised about $10-20 million online in his first month after winning the nomination, $20-30 million in the second month and as much as $50-60 million in the third.
Noting that Mitt Romney, who never excited grassroots supporters like Trump does, still managed to raise close to $200 million online in 2012, the strategist guessed that Trump had the potential to pull in between $250 and $350 million online with the right time and infrastructure.
But having already missed key opportunities, the strategist guessed Trump's final number will be closer to $100 million.
"He waited too long," agreed Greg Greene, a digital operative at the Democratic National Committee during the 2012 campaign.
Trump's campaign has dramatically picked up the pace of its email solicitations in the past two weeks and said it raised $3.3 million off a single email (though some doubt that figure).
"We have a tremendously successful fundraising operation in place, and we are excited about the overwhelming response we've received over the past several days. We expect this to continue," Trump spokesperson Hope Hicks told NBC News. Hicks and the RNC did not respond to more specific questions.
Still, it takes time and sophistication to build an email list, the backbone of an online fundraising operation. Lost time and non-optimized efforts translate to lost potential donations from people who might be interested in giving to Trump, but whom the campaign never reached.
That forces Trump to rent other people's lists, which are often degraded by the time they're made available to renters. For instance, Trump sent an email to Ben Carson's email list this week with the subject line: "Breaking: Hillary to be indicted in November."
Trump's first email solicitation is a good example of the larger issues, operatives say.
Trump clinched the Republican presidential nomination on May 26, but didn't send his first real fundraising email until June 21. "This is the first fundraising email I have ever sent on behalf of my campaign. That's right. The FIRST ONE," Trump proclaimed in the message.
In a campaign about six months long, not only did Trump entirely miss a full month of potential fundraising, but he missed the opportunity to fundraise off his primary victory -- the kind of high-visibility moment that email marketers live for and when donations spike.
Meanwhile, that email made what AdAge called a "rookie mistake," which resulted in it landing in the spam folders for about 60 percent of recipients. "These are things that professional email marketers prepare for," said Tom Sather of the email marketing firm Return Path.
Experts point to numerous other missteps, like a website that makes it relatively difficult to sign up for emails; the apparent lack of email testing capabilities; and the campaign's decision to offer a donation match on their first email, which could depress interest in future emails without matches.
Even if he fixes the technology, Trump has a message issue, since the billionaire has spent months telling his supporters he doesn't need help from anyone.
"One of the reasons Bernie Sanders was so successful is that small donors want to feel needed," according to Ari Rabin-Havt, who has run email programs for John Kerry and other Democratic campaigns. "Trump has consistently told small donors their donations are not needed."
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Both parties agree Democrats are well ahead of Republicans in terms of digital fundraising. Obama more than tripled Romney's haul in 2012. ActBlue alone has helped Democrats raise more than $1 billion and has saved info on 3 million donors to facilitate Democratic campaigns.
And some Republicans worry Trump will dampen their efforts to catch up.
"We're fighting with one hand tied behind our back," said the GOP strategist who asked not to be named.
Despite all that, Trump has a knack for upsetting expectations. "In terms of the raw numbers where he stands today, Trump would appear to be at a tremendous disadvantage from an email list size and fundraising perspective," said Jordan Cohen, the Chief Marketing Officer at ad technology firm Fluent. "However, his campaign has defied the conventional logic across many different vectors and I wouldn't dismiss his ability to be able to radically grow his list as soon as they start to make it a focus."