This June, Talking Points Memo had the biggest ad sales month in its eleven-year history, closing out a half-year period that saw ad sales revenue grow 88 percent over the same period in 2010.

First of all: Yowza. Second of all, though: That number, while big, isn’t entirely out of left field. “We’ve been growing at double-digit — sometimes approaching triple-digit — growth ever since we started our direct-sales ad program,” TPM’s founder/editor/publisher, Josh Marshall, told me. So while the 88 percent stat is a record, and “we love that number,” he notes, it’s also “not dramatically different from what we’ve had in previous years.”

Still, though, it’s worth a moment of pause. Because here is a web-native news organization that started as, you know, Some Guy’s Blog and that is now able to sustain itself — actually, grow itself — based on digital ad revenue. At a time when many news publishers are struggling in a sea of digital dimes, TPM, it seems, is finding a way to turn those dimes into dollars.

Marshall attributes the success largely to TPM’s organizational double-down on direct ad sales. In 2009, as it expanded its presence in D.C., the site — which had previously relied on networks like Blogads to support its operations — began investing in in-house advertising efforts, bringing on a sales VP and taking advantage of TPM’s famously loyal user base to make a compelling pitch to advertisers. And at higher CPMs.

“The big thing is really talented people doing the sales,” Marshall says.

And another thing is time: Ad sales are about relationships, and cultivating them can’t happen overnight. The real growth of TPM’s ad sales numbers really “started to kick in after we’d had some time to tell the advertisers about the site, about the value proposition of advertising with us,” Marshall notes.

And a big part of that proposition is the thing that advertisers are actually buying when they sign on with TPM: the TPM audience, the collective of dedicated (and also, generally: affluent, educated, influential) people whose eyeballs advertisers generally want to reach. Advertisers so far have included big national brands like Toyota, BP, HBO, Goldman Sachs, and CVS; media outlets like Current TV, The New York Times, and the Wall Street Journal; and organizations like Harvard Business School, America’s Natural Gas Alliance, the Association of American Railroads, the American Council of Life Insurers, and the Obama 2012 Re-Election Campaign. (That last group is a big part of TPM’s ad strategy, particularly for its D.C.-based audience. The advocacy market tends to have deep pockets — and “everybody wants to have their story told to the people who are calling the shots, who live in D.C.,” Marshall points out.)

But TPM’s readership isn’t limited to the District (indeed, this has been a pretty good month to remind us that Washington news is national news), and part of TPM’s pitch is that its audience nationwide is particularly engaged with its content and mission. (And also, again: affluent, educated, influential.)

And that’s evidenced in part by an annual reader survey that TPM conducts, consisting of over 30 questions, asking readers to send TPM data about themselves and their reading habits. TPM’s 2011 survey was introduced with a quick request for completion from Marshall; it was live for 24 hours; and it received, Marshall told me, some 26,000 completed results.

Again: Yowza.

So TPM offers not just a quality audience, in terms of the demographics advertisers like, but also a highly — even hyper- — engaged one. Readers often visit TPM multiple times a day. They trust it. They consider themselves, often quite literally, to be a part of it. Because of all that, Marshall says, “we have a great story to tell to advertisers.”

It’s a story, sure, that’s a fairly unique one in today’s news environment. Political coverage of the depth and intensity TPM offers may lend itself to reader engagement; it’s also hard to duplicate, though, especially at more general-interest publications. But as news outlets big and small, general-interest and niche, consider their futures, TPM’s experience can be instructive — not only editorially, but also financially. There are basically two TPMs: There’s TPM, the new media visionary and crowdsourcing pioneer and Polk Award winner and “prototype of what the successful Web-based news organization is likely to be in the future“; and then there’s TPM, the scrappy startup that is trying to make a viable business of web-native political reporting. TPM’s ad-sales success suggests the tantalizing possibility that, even in today’s murky media environment, TPM 1 and TPM 2 can actually be the same thing.