At PandoMonthly in New York tonight, WordPress founder Matt Mullenweg said the page-view mentality is “poisonous” and in-stream advertising is the future.

Speaking to Sarah Lacy, Mullenweg confessed to using an ad blocker when browsing the Web. Publishers get angry at that technology because they think it erodes their money-making ability, he said. But they need to recognize that “it’s the page-view model that’s broken.”

Publishers are getting low value from display advertising, which is often sold on the strength of how many page views they can accrue. “The people who click on ads are not the people who are buying,” Mullenweg said. “The people who click on those ads typically aren’t the most tech-savvy, they aren’t the most affluent.”

The future of advertising, he said, is in-stream. Companies like Facebook, Twitter, and Tumblr, which have rich streams that get a lot of attention, are best placed to capitalize on this new breed of advertising. “It’s like a magazine,” he said. “It’s not that bad to see an ad for a page or two because you can just turn the page.”

Traditional Web advertising models will quickly become outdated, he said. “The first’s thing that’s going to die is above-the-fold. It doesn’t matter at all.”

That news will be music to Facebook’s ears in the wake of its almost farcical IPO. Critics have suggested that Facebook is too reliant on advertising and that its bread-and-butter display ads underperform. That complaint was at the root of GM’s decision to withdraw a $10 million advertising campaign from Facebook in the week leading up to the IPO.

Earlier, Mullenweg said Facebook and Twitter have actually improved the prospects of blogging, contrary to opinions that microblogging would kill the old-school publishing form. On the contrary, the social networks actually whets people’s appetites for more, he said. “Every single blogging system has been growing or accelerating since Twitter started.” Meanwhile, social networks serve as great distribution platforms for bloggers who want to attract readers.

Hear that? It’s the lonely chirp of someone being bullish on Facebook.