They are very upfront about their business model. Submitters (people who want stories promoted) pay $20 plus $1 per digg. Users (digg users who’s second job as a WoW gold farmer is getting tedious) get paid about 17c per digg. So buying 100 diggs costs $120, and in theory nearly $17 of that gets paid out to diggers, there is a $20 payout minimum, so the chances of many people diligently digging away and making 120 paid diggs before their account gets noticed and shut off seems unlikely. In either case, it is nice profit margin while they can get away with it.
Digg unsurprisingly don’t seem to be fans. Poking around, I can see accounts are being disabled. One of mine got disabled, but that might be a bad example because I was not very subtle. Commenting on stories that I dugg that I had dugg them for 17c is probably more blatant than most. Result:
Looking at other accounts with suspicious behaviour though I see a few of these:
Privacy is not particularly well guarded at User/Submitter. If you want to know if a digg user name is registered there, then try to register it. An interesting username to try is kevinrose.
Of course, the experiment is somewhat flawed. You can only check once, and while a negative result is definitive, a positive result might just mean that somebody else performed the same experiment before you. Rumours of Digg’s demise might be popular, but I don’t think Kevin yet needs a side job paying 17c per click.
Suspicious behaviour though is not hard to find. Here are a list of Digg stories that received paid Diggs in the last few hours.
Unsurprisingly, there are a number of the same users digging many of them.
What a social site should do about abuse is a harder problem. Any competitive environment is bound to get people gaming or abusing the system. I am not sure that disabling accounts is the best solution though. If I was a 3rd world subsistence gold farmer sitting in an internet cafe clicking links for a few cents a time and my account got disabled I would just create a new one that needs to be detected and disabled. If my account silently got flagged as a source of worthless diggs, and just ignored in calculations, then I would merrily continue clicking away and over time nearly all bought diggs would be worthless because they would mostly be being paid out to account that have already been detected.
Publicly disabling accounts is good for maintaining the appearance of transparency, but longer term, allowing abusive users individual sandboxes to play in lets them waste time without affecting others. In a system where reregistering under another alias is painless, disabling accounts is not a very effective deterrent.