Until now, staff at the section, which was formerly known as Talking Point and which invites comments on issues in the news, had edited and formatted submissions received by email before selecting just a handful for publication.
But with the new system, inspired by weblog feedback mechanisms, users will be able to post their comments straight to the site, bypassing the BBC's journalist moderators.
"Running at around 10,000 emails a day we just do not have enough journalistic eyeballs looking at the inbox," writes Vicky Taylor, interactivity editor for the site.
"As the site has grown beyond anyone's wildest dreams, so have the number of people contributing to our debates."
The revamp debuted last Monday with a pilot debate on identity fraud and, to combat alarm about opening the site to just anyone, employs two methods of self-policing that, like Wikipedia, rely on the collective integrity of the readership.
Users can vote fellow readers' comments to the top of the feedback list with a "recommend" button, ensuring the best responses are more prominent while others are drowned out. Meanwhile, responses deemed offensive by readers can be flagged up to the editorial staff with a "complain about this comment" facility.
The BBC has long operated policies of either pre- or post-moderating message board comments while BBC News had operated only pre-moderation. Now Have Your Say debates will be either "reactively moderated" by its own users or "fully moderated", with journalists checking for libel and profanity as before - but not spelling and grammar - depending on the nature of the story.
"In the first four debates using the new system, we published just fewer than 2,000 emails - that is a ten-fold increase on normal," Ms Taylor told Journalism.co.uk.
"It's been a really interesting week, and we could not be more pleased with how it has gone. We have had more than 1,000 people registering, so already it has delivered one of its key objectives - more voices on our site.
"We are learning that by far the vast majority of comments are interesting, intelligent and informed and the odd grammatical mistake is acceptable against the vast improvement of accessibility."
All debates will be moved to the new platform by November.
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