Found this June 10 Parscale interview with 60 minutes (has transcript as well as video for those who prefer to read,) very interesting in that he clearly still is a true believer Facebook is what helped them win, espec. the micro-targeting, with Facebook staff helping them learn "how to", like this (my underlining):

[....] Brad Parscale: I understood early that Facebook was how Donald Trump was going to win. Twitter is how he talked to the people. Facebook was going to be how he won.

Lesley Stahl: And Facebook IS how he won.

Brad Parscale: I think so.  I think Donald Trump won, but I think Facebook was the method -- it was the highway in which his car drove on. [....]

And Brad Parscale was in the driver's seat.  In the beginning of the campaign he worked alone at home in San Antonio, but by the end he had 100 people reporting to him. One of his main jobs was to send out carefully-tailored, low-cost digital ads to millions of people.

Lesley Stahl: And these were ads on Facebook?

Brad Parscale: Facebook, we did 'em on Twitter, Google search, other platforms. Facebook was the 500-pound gorilla, 80 percent of the budget kind of thing [....]

Lesley Stahl: One of the best things Facebook did for you, I heard, was penetrate the rural vote. Is that correct?

Brad Parscale: Yeah. So Facebook now lets you get to places and places possibly that you would never go with TV ads. Now, I can find, you know, 15 people in the Florida Panhandle that I would never buy a TV commercial for. And, we took opportunities that I think the other side didn't.

Lesley Stahl: Like what?

Brad Parscale: Well, we had our-- their staff embedded inside our offices.

Lesley Stahl: What?

Brad Parscale: Yeah, Facebook employees would show up for work every day in our offices.

Lesley Stahl: Whoa, wait a minute. Facebook employees showed up at the Trump headquarters --

Brad Parscale: Google employees, and Twitter employees.

Lesley Stahl: They were embedded in your campaign?

Brad Parscale: I mean, like, they were there multiple days a week, three, four days a week, two days week, five days a week --

Lesley Stahl: What were they doing inside? I mean --

Brad Parscale: Helping teach us how to use their platform. I wanna get --

Lesley Stahl: Helping him get elected?

Brad Parscale: I asked each one of them by email, I wanna know every, single secret button, click, technology you have. "I wanna know everything you would tell Hillary's campaign plus some. And I want your people here to teach me how to use it."

Lesley Stahl: Inside?

Brad Parscale: Yeah, I want 'em sittin' right next to us --

Lesley Stahl: How do you know they weren't Trojan Horses?

Brad Parscale: 'Cause I'd ask 'em to be Republicans, and I'd -- we'd talk to 'em.

Lesley Stahl: Oh, you only wanted Republicans?

Brad Parscale: I wanted people who support Donald Trump from their companies [....]