When the Democratic National Committee (DNC) introduced individual donor thresholds earlier this year for candidates to qualify for primary debates, it was trying to empower campaigns with grassroots support. But these new rules have also created a massive online audience acquisition spree. The first round of debates was relatively easy to qualify for – with candidates only needing 65,000 individual donors or to notch 1% in three DNC-approved polls. But the requirements for the next debate stage in September require candidates to accrue 130,000 individual donors and hit 2% in four polls. “NPR just warned the Detroit debate could have been my last,” according to one Julián Castro Facebook ad following the Democratic debate last week. “I need a massive surge of support … to qualify for the next round and prove we’re in this for the long haul.” Sen. Kirsten Gillibrand’s campaign is also scouring Facebook to clear the donor minimum. “We’re so close to qualifying for the September debates. Help us get there by becoming a donor. Even $1 helps.” The rules have also created an unusual dynamic for wealthy, self-funded campaigners like John Delaney and Tom Steyer, the billionaire activist who entered the race last month, who need to rack up new donors but not the donations. The result is a direct response marketing feeding frenzy on Facebook.

Democratic primary campaigns are offering fundraising vendors and social platforms between $50 and $200 per new individual donor, according to four people with knowledge of the deals.

Offering $100 or more for a one-time $1 donor makes no commercial sense, but the DNC debate threshold creates a new rationale for primary campaigns.

In the first two weeks after Steyer entered the race, the campaign made the largest television buy of the primaries so far and cleared the DNC polling requirements. If the campaign could spend $20 million to bring on 130,000 donors (roughly $150 per conversion), it would be money well spent.

“With the DNC rules, suddenly the digital directors are some of the most important people in these campaigns,” said Mark Jablonowski, CTO of the liberal ad tech company DSPolitical.

There are only a few million Americans who donate to Democratic primary campaigns, said Brian O’Grady, principal at Clarify Agency, a liberal media and fundraising firm.

“All 20 candidates are going for the same two or three million people,” he said. “And they’re using the same tactics and competing for the same Facebook impressions.”

O’Grady said the company, which works for Bill de Blasio's presidential primary campaign, has seen CPMs shoot up and acquisition rates drop since March, when the primaries started heating up and competing for donors.

“From our perspective, the primaries sucked up all the fundraising oxygen unless you’re working for a candidate,” said Keegan Goudiss, head of advertising at the liberal firm Revolution Messaging, who was also Sen. Bernie Sanders’ director of digital advertising in 2016.

One large liberal advocacy group that’s running new donor campaigns with Revolution has pulled spend the day-of or right after debates, or during other big-spending times for campaigns, like at the end of the financial disclosure periods, because acquisition rates become untenable, Goudiss said.

In two weeks, when candidates are coming up to the deadline to reach 130,000 individual donors, they will likely clear out any other liberal online acquisition campaigns.

“August is usually one of the most cost-effective months to advertise,” Goudiss said, because brand advertising slows down and political candidates are in a quiet period after their quarterly disclosure at the end of July. “But rates right now are showing no sign of rationalizing.”