Brad Parscale tells CBS ‘Twitter is how [Trump] talked to the people’ but says staff members from other social media giant helped with targeted advertising.

The Trump presidential campaign spent most of its digital advertising budget on Facebook, testing more than 50,000 ad variations each day in an attempt to micro-target voters, Trump’s digital director, Brad Parscale, told CBS’s 60 Minutes in an interview scheduled to air on Sunday night.

“Twitter is how [Trump] talked to the people, Facebook was going to be how he won,” Parscale said.

Facebook provided Trump 2016 with employees who embedded in the campaign’s digital office and helped educate staffers on how to use Facebook ads, he said. Because he “wanted people who supported Donald Trump”, Parscale said, the Facebook employees were questioned on their political views.

On Sunday night, Facebook addressed Parscale’s comments publicly, saying in an update to a post on its Hard Questions blog about elections that the company gave support impartially to a range of campaigns.

“Campaigns aren’t able to hand-pick Facebook team members to work on their projects,” the statement read, in apparent reference to Parscale’s claim, as reported by CBS, that the Facebook employees that served as “embeds” in his office “had to be partisan and he questioned them to make sure”.

Parscale said the Trump campaign used Facebook to reach clusters of rural voters, such as “15 people in the Florida Panhandle that I would never buy a TV commercial for”.

“I started making ads that showed the bridge crumbling,” he said. “I can find the 1,500 people in one town that care about infrastructure. Now, that might be a voter that normally votes Democrat.”

Parscale said the campaign constantly tested minute variations in the design, color, background and phrasing of Facebook ads, in order to maximize their impact. Typically 50,000 to 60,000 variations were tested each day, he said, and sometimes as many as 100,000.

In the realm of digital campaign advertising, micro-targeting of voters and constant testing of the effect of minute differences in ads are not new or innovative actions.

But Parscale’s comments highlight how actively Facebook has pursued election advertising as a business strategy, even as its platform has come under attack as a fertile ground for Russian-backed political propaganda, conspiracy theories and other forms of disinformation.

Among other services, Facebook’s elections advertising allows campaigns to takelists of registered voters drawn from public records and find those people on Facebook.

Parscale said he asked the Facebook “embeds” to teach staffers everything the Clinton campaign would be told about Facebook advertising “and then some”.

On Sunday, a Facebook spokesman said the support the company offered the Trump campaign was standard practice, both for Facebook and across other industries.

“For candidates across the political spectrum, Facebook offers the same levels of support in key moments to help campaigns understand how best to use the platform,” spokesman Andy Stone wrote in an email.

Parscale told CBS he was told the Clinton campaign did not use Facebook employee embeds. “I had heard that they did not accept any of [Facebook’s] offers,” he said.

According to Facebook, it afforded the Clinton campaign the same level of support as the Trump campaign. Stone, the spokesman, wrote: “While Facebook teams offer insight into how our products work, campaigns make their own strategic decisions about how to use the Facebook platform.”

Before the 2016 election, Bloomberg reported that some Trump campaign ads were designed to dishearten potential Clinton supporters, including women and African Americans, actions that in the words of a senior Trump campaign official constituted “major voter suppression operations”.

One Facebook ad the Trump campaign aimed at some African American voters, Bloomberg reported, was an animation of Clinton talking about “juvenile super predators” in 1996, with the caption: “Hillary Thinks African Americans are Super Predators.”

Transparency regulations for Facebook ads are being debated in Washington. In 2011 Facebook succeeded in having its ads classified as small campaign items, like buttons, that did not require an official disclosure to the Federal Elections Commission (FEC) like other campaign advertising. That decision has come under attack. The FEC is reviewing it.

Parscale told CBS he believed liberal tech company innovators were surprised and shocked by how their platforms had been used to “push conservative values”.

“These social platforms are all invented by very liberal people on the west and east coast,” he said. “And we figure out how to use it to push conservative values. I don’t think they thought that would ever happen.”

It is not clear why tech companies would be shocked that products they aggressively marketed to conservative and liberal campaigns would be used to elect Republicans.

Excerpts of the interview did not make clear if Parscale offered any data to back up his suggestion that Facebook ads targeting 15 people at a time were “how Trump won”.

Digital advertising experts have cautioned for years that when talking to the media, campaign strategists often over-hype the sophistication of “micro-targeting” and similar digital efforts.