Wired Digital, parent company of the Wired.com technology portal, has acquired the Reddit social news service for an undisclosed sum. 

Reddit was founded at around the same time as Digg. Although the service has a loyal user base, it attracts significantly less traffic. 

Reddit's four employees will move to Wired's San Francisco office, but the site will continue to operate autonomously, the company said on its blog. 

"We are still going to be the guys reading your feedback emails and keeping Reddit chugging along," they said. "With Wired's resources, we are looking to do some neat things in the coming months."

Similar to Digg, Reddit allows users to submit content and vote for the most interesting story. Popular stories are promoted to the front page.

Reddit is different from Digg in that it also allows users to disapprove of submitted content. A negative vote decreases a story's overall vote count as well as the 'karma score' for the user who submitted the URL. 

Karma scores are further affected by users voting on comments. Reddit claims that the score is used for bragging rights only.

Digg has stated in the past that it uses a karma score to tackle spam. Users gain karma points when the stories they submit are promoted to the front page. A user's karma score is then used to weigh their vote.

Critics have charged that this systems has spawned a group of elite 'Diggers' who can effectively control which stories end up on the front page.