She met Glazer, who plays the wilder of the two, about seven years ago, while taking classes at New York's Upright Citizens Brigade, the theater and training facility that Poehler co-founded.
"You start to form these practice groups outside the community," she said. "You're trying to get on the [UCB] house team at the theater, but you need to be performing.
"Ilana and I were the only two girls on [their] team," and they became friends, performing for the next couple of years in small theaters all over New York.
"You buy out a space and sell tickets and hope you make your money back," Jacobson said.
Not that that was her only job.
"When I moved to New York, I always wanted to work at Anthropologie, because [the retail chain] started in my town. . . . I remember asking specifically to work in the Rockefeller Center one because that's where ["Saturday Night Live"] was and I got to sort of be there. Even though I was selling clothes."
But after a couple of years of performing, Jacobson said, "We were getting frustrated. We can't get on these house teams at the theater, and my parents are like so supportive but they're also like, 'You're doing improv and . . . you're paying to perform.' They're not seeing me perform."
So she and Glazer decided to "write material for ourselves and put it up online somehow. We didn't know what it would be [but thought], 'What if it's just [about] us?' Because our friendship was so quick . . . but it was also very different than my other friendships because we were both [comedians] and all my other friends were not doing comedy. It was just like a specific dynamic where we, like, agreed to disagree about stuff. We don't always get along, but we're never fighting."
They started "meeting to come up with ideas about little situations that happened to us in New York," she said. "And then we started asking, 'How are we going to do this? We don't have cameras, we don't edit.' We started asking people in the UCB community to get involved and help us. And we just kept making them. We made two in the fall of '09, I think, put them out right in the beginning of 2010 and just got great feedback from our community in New York."
And from home as well.
"I come from an arts background. My brother's a graphic designer, my dad [Alan] is a graphic designer and my mom [Susan Komm] is a found artist, an object artist. So they were always really supportive" of her ambitions, even after she abandoned fine arts - she's a graduate of Maryland Institute College of Art - to pursue comedy.
" I think they [were] just happy that . . . I'm putting something out there," she said. "All their friends watched all the Web episodes as they came out, which is very cool."
Komm even appeared in an episode of the Web series, along with Glazer's mother, titled "Mom Brunch."
But it was another, slightly more famous guest star who helped Jacobson and Glazer take "Broad City" to a broader audience.
"Jump to 2011, we've been doing it for a year and a half, we're in the second season of the Web [series] and we had written a pilot, and we were planning on going to LA in the summer of 2011 to pitch it, at the same time ending this Web series. We had this finale . . . we wanted to ask somebody special" to be in it, Jacobson said.
They asked a "friend to ask [Poehler], and she said yes. And it was as crazy as you could imagine. She did the episode with us and we really hit it off. And then . . . we asked her, again on a whim, if [she] would ever consider being an executive producer, we have a pilot we're going out to pitch. And she said, yes, again, and it was even more crazy. So we ended up going out in August, as we planned, but now we have Amy Poehler."
They first "sold a script commitment to FX," which ended up passing, "but we went out and pitched again, Comedy Central picked it up, we reworked the script with them, made the pilot and then the rest is - who knows?" she said.
"Television's such a great medium for women," said Poehler during a Comedy Central session for the show, two days before she and Upper Darby's Tina Fey hosted the Golden Globes. "And what I like about 'Broad City' is that we have, like, very kind of interesting, real female friendships and sexual . . . premises that aren't like, the headline of the show."
Which is, maybe, a nice way of saying that while it can be frank, "Broad City" isn't HBO's "Sex and the City." Or "Girls."
Jacobson, who's a fan of the much-written-about Lena Dunham show, thinks that they're just different kinds of funny.
What she loves about "Girls": that Dunham has "captured how your early 20s might be like what years ago your teens were. She knows exactly that that's kind of f---ed up. She's really smart."
On Twitter: @elgray