"Rookie" strives to be an authentic forum for the issues facing teenagers and is published on a schedule that is tailored to a high-schooler.
"We post after school, around dinner time and around bed time," Gevinson said. "When we were starting this, my dad was like, 'How are you going to do this? You are in school during the day,' and I was like, 'Well, so is everybody else so I'll just post when we all get home.'"
The site has such cachet it has attracted high-profile contributors like HBO "Girls" creator Lena Dunham, comedian Sarah Silverman. And, for the girl who loves the '60s "Mad Man" aesthetic, even the AMC show's star, Jon Hamm.
While wearing a 5 o'clock shadow and a St. Louis Cardinals t-shirt, the "Mad Men" actor gave "Rookie" readers hysterical, but honest, advice about what boys are thinking in a Q&A session. Hamm answered one question from a 16-year-old girl who asked what she should do about being ready to "do stuff" with her boyfriend of three weeks when he didn't want to.
"I am going to have to know what this [air quotes] stuff is," Hamm said. "If it is making out, he should want to do that, it's super fun. If it's having sex, that has other things to deal with. Then he's probably right to say slow your roll."
"His thing was that he is sort of very uncomfortable answering these questions about sex from teenage girls and that worked out great," Gevinson said.
But the uber-literate, style-conscious teen does admit to having weak spots. For one, she said she is a "horrible" driver who failed her driving test. And yet, she has employees who work for her, some of whom are in their 40s.
"They are all there because they take our audience seriously," Gevinson said. "At the risk of sounding cheesy, there is a lot of love that goes into working on 'Rookie' and it absolutely would not work if the people working on it didn't respect the intelligence of teenagers."
The truth is that teenagers are complicated. They are a bundle of contradictions, bravado laced with insecurity, with moments of joy and angst.
"Being a teenager is just, kind of, inevitably horrible," Gevinson said. "But I think a lot of the sadness or angst or any of the problems teenagers deal with are often sort of brushed aside because they are teenagers so people think, 'It's just a phase,' or, 'He or she is just being a teenager.'"
It's that kind of raw honesty that makes Gevinson an inspiration to young girls.
Some parents have asked me, 'This book has a lot of serious stuff in it; is it OK to give my daughter?'" she said. "And I feel like those are already things that like 12-, 13-year-olds know about and are talking about with their friends. And here is at least one person's honest account of it."