Josh Marshall, the founder and editor of Talking Points Memo, just spoke by webcam to a conference at Kent State University, and it was a revealing discussion. He said that TPM’s readership is now at 1.8 million unique visitors per month, which is up from the 1.5 million he told me in July. “We’ve had a lot of growth over the past six months or so,” Marshall said.

He also revealed a datapoint that I hadn’t come across before: 65% of TPM’s audience is male, and Marshall said the gender skew used to be even more dramatic. (It’s also pretty affluent.) The same appears to hold true for rival Politico, which has a 69% male readership, according to Quantcast’s estimate. I don’t know what, if anything, to make of that, but it’s certainly important to understanding the market for online political news.

TPM just embarked on a major expansion, hoping to grow its staff to 18 or 19 within the next year and 60 in three years. (Needless to say, they’re hiring.) So I was interested to hear Marshall say this about his broader ambitions: “By 2012, there will be a dozen or so national publications driving the conversation in this space — what I described as serious political news, national news — and we want to be one of those news organizations.”

If Marshall is right, which news outlets will be part of that dozen in 2012? I could guess, but it will definitely include some names we haven’t heard of yet.