Buying votes on Digg

Annalee Newitz at Wired writes "I Bought Votes on Digg", an article about how she bought votes to get "a pointless blog full of poorly written, incoherent commentary ... to the front page on Digg."

Matt Marshall has a nice summary of the Wired article, ending with the comment, "This is particular harmful for Digg, because its management has said gaming can't happen."

Security guru Ed Felten posts some good thoughts on the Wired article and, more generally, on manipulation of community reputation systems. Some excerpts:

There's a myth floating around that such [reputation] systems distill an uncannily accurate folk judgment from the votes submitted by millions of ordinary citizens. The wisdom of crowds, and all that.

In fact, reputation systems are fraught with problems, and the most important systems survive because companies expend great effort to supplement the algorithms by investigating abuse and trying to compensate for it.

The incentive problem is especially challenging for recommendation services like Digg. Digg assumes that users will cast votes for the sites they like. If I vote for sites that I really do like, this will mostly benefit strangers.

But if I sell my votes or cast them for sites run by my friends and me, I will benefit more directly. In short, my incentive is to cheat. These sorts of problems seem likely to get worse as a service grows, because the stakes will grow and the sense of community may weaken.

See also my earlier post, "Spam is ruining Digg", and its many references to other posts about spam, Digg, and reputation systems.