I was invited to be a part of pigg.com. Basically what they did was to automate the
digg (and stumble) process. What you did as a member was to earn points by digging
and stumbling other members - and once you've gotten enough points, you could then
submit your URL. Basically this inflated your diggs to as many members that were online
to do so.
Now
my main site and one of it's PR5 sub-domains cannot be dugg anymore
I've actually contacted digg for a re-inclusion of that site, but so far they have not
responded.