In a letter to publishers, Digg product manager Mike Cieri announced that the troubled social news website will no longer accept content submitted via RSS.

The ability for publishers to submit all of their stories to Digg automatically using an RSS feed seemed like an efficient way to open up a firehose of content for Digg. However, Cieri says this idea had unintended consequences.

According to Cieri, "Most RSS-submitted content is not performing well on Digg." He says the site's analytics show that only a mere 4.5% of Digg's "Top News" content comes from the RSS submissions. He adds that the ability to submit an RSS feed to Digg "has been heavily abused by spammers and has been a constant drain on our technical resources to identify and fight off spam content." Cieri praised the manual method of submitting stories to Digg, saying that manual submissions "ensure that quality content appears on Digg."

With this move, the site takes yet another step back toward the old version 3.0, the site design that was in use before radical changes resulted in a user revolt and a 24% decline in U.S. visitors in the first 11 weeks. In response, Digg has slowly added back features that readers missed, such as the ability to bury stories, and last month's overhaul that included the return of user profiles and story statistics. Since that first fateful redesign last summer, Digg has laid off more than a third of its staffers.

I'm just wondering why Digg stubbornly refused to modify its obviously unpopular redesign after it became apparent that it was resulting in large percentages of its readership turning away. After a few days of this, why didn't Digg simply revert to the old version and its rules that seemed to be working pretty well? If not a few days later, why not a month later? Comments?

Here's the full text of the letter we received from Digg product manager Mike Cieri: