I find these results surprizing. I’ve had half-a-dozen entrieson the front page of Reddit, with each yielding from 2500-5600distinct referrals per day. In comparison, I’ve had a front pageentry on Digg for a day, only bringing in ~750 referrals.
Of course, a single entry isn’t a very good sample, and it’sentirely possible that most people just weren’t interested in thelink — that it was a fluke that it got on the front page in thefirst place — but I’ve seen several other stat watchersmention very similar stats (that a front-page of Digg yielded them800 or so visitors per day), so I’m not basing this comment simplyon my own observation. I’ve looked for exceptions to this, andfound one individual who had a broad-interest link atop Digg’sfront page for 24 hours straight, and they claim that for that daythey received a total of 7200 distinct referrals, and then itrapidly tailed off, disappearing in two days. That case seems to bethe exception.
One possibility is that Digg offers more linkdiversity and thus the much greater traffic is dispersed,significantly reducing the impact on any one link. Alternately,perhaps Digg users spend more of their time within the Diggcommunity, rather than following the links (in the same way thatmany Slashdot readers just make assumptions about the linkedarticle, responding accordingly, rather than RTFA).
Another possibility is that Digg caters to a crowd that is morelikely to have the Alexa/A9 toolbars installed, both of whichfeed back the stats that are used to drive theAlexa popularity metrics. Given that they’re somewhatinfrequently used toolbars, and are much more likely among certaincrowds (and seems to appear in clusters), the traffic rankings area bit of a crapshoot outside of the top sites — Here on yaflaI’ve had days with 6000 visitors where my Alexa ranking doesn’tbudge, whereas other days 2000 visitors cause it to quintuple.